1. A preparation method of an unbonded integrated titanium carbide material is characterized by comprising the following steps: the method comprises the following steps:

(1) providing a carbon nanotube film;

(2) preparation of hydrated titanium/carbon nanotube film

Immersing the carbon nanotube film into a titanium source solution, performing electrochemical deposition, and drying a deposited sample to obtain a hydrated titanium/carbon nanotube film;

(3) preparation of titanium carbide nanotube film

Carrying out primary high-temperature heat treatment on the hydrated titanium/carbon nanotube film in a protective atmosphere to obtain a titanium carbide nanotube film;

(4) preparation of non-bonding integrated titanium carbide material

Embedding the titanium carbide nanotube film in graphite powder, and carrying out secondary high-temperature heat treatment in a protective atmosphere to obtain the unbonded integrated titanium carbide material.

2. The method for preparing the unbonded integrated titanium carbide material according to claim 1, wherein the method comprises the following steps: in the step (1), the thickness of the carbon nanotube film is 20-40 μm, and the specific surface area is 100-150m² g^-1。

3. The method for preparing the unbonded integrated titanium carbide material according to claim 1 or 2, wherein the method comprises the following steps: preparing the carbon nanotube film by floating catalyst chemical vapor deposition method in step (1), preferably, Ar/H₂Introducing mixed gas, introducing ethanol solution of 1-2% of ferrocene and 0.1-0.5% of thiophene at the volume fraction of 10-30 ml/h into a reactor at 1200-1300 ℃, and collecting layer by layer through a wheel rotating perpendicular to airflow to form a randomly oriented 20-40 mu m thick carbon nanotube film.

4. The method for preparing the unbonded integrated titanium carbide material according to claim 1, wherein the method comprises the following steps: in the step (2), the titanium source solution is a titanium salt aqueous solution, preferably TiCl₃Aqueous solution, pH adjustmentTo 1.0-2.0; optionally, the electrochemical deposition is performed for 400-1000 seconds at a constant potential of 0.5-1.0V; and drying the deposited sample at 60-100 ℃ for 24 hours under vacuum to obtain the hydrated titanium/carbon nanotube film.

5. The method for preparing the unbonded integrated titanium carbide material according to claim 1, wherein the method comprises the following steps: in the step (3), the temperature of the primary high-temperature heat treatment is 1200-1300 ℃, and the time is 5-10 hours; preferably, the primary high temperature heat treatment comprises: firstly, vacuumizing the reactor, then introducing protective atmosphere to atmospheric pressure, heating to 400-500 ℃ at the speed of 1-10 ℃/min, calcining for 1-2 hours at the temperature, heating to 1200-1300 ℃ at the speed of 1-10 ℃/min, and calcining for 5-10 hours at the temperature to obtain the titanium carbide nanotube film.

6. The method for preparing the unbonded integrated titanium carbide material according to claim 1 or 5, wherein the method comprises the following steps: in the step (4), the graphite powder is high-purity graphite powder with the size of 8000-;

optionally, the temperature of the secondary high-temperature heat treatment is 1200-1300 ℃, and the time is 10-15 hours; preferably, the secondary high temperature heat treatment includes: firstly, vacuumizing the reactor, then introducing protective atmosphere to atmospheric pressure, heating to 400-1300 ℃ at the temperature of 1-10 ℃/min, calcining for 1-2 hours, heating to 1200-1300 ℃ at the temperature of 1-10 ℃/min, and calcining for 10-15 hours at the temperature to obtain the unbonded integrated titanium carbide material.

7. The unbonded integrated titanium carbide material prepared by the method for preparing the unbonded integrated titanium carbide material disclosed by any one of claims 1 to 6.

8. The unbonded integrated titanium carbide material of claim 7, wherein: the titanium carbide nano-tube three-dimensional interconnection network comprises a titanium carbide nano-tube three-dimensional interconnection network and a titanium carbide nano-layer, wherein the titanium carbide nano-tube three-dimensional interconnection network is of an inner layer structure, the titanium carbide nano-layer is wrapped outside the titanium carbide nano-tube three-dimensional interconnection network, and the adjacent titanium carbide nano-layers are interconnected.

9. An electrode comprising the unbonded, integrated titanium carbide material of claim 7 or 8.

10. A supercapacitor comprising the electrode of claim 9.

Background

The supercapacitor is an electrochemical capacitor having a high power density (5-30 kW kg) compared to a lithium battery^-1Charge cycle<1 minute), cycle life of more than 10 ten thousand times, good low-temperature performance and the like. However, the energy density of supercapacitors is low (5-8 Wh kg)^-1) And the hybrid power battery automobile can not be used as an electric automobile energy source independently, and can only be used as auxiliary energy source to provide short-time power at present, such as a hybrid power fuel battery automobile which takes a super capacitor produced by Japan Honda and other companies as the auxiliary energy source.

In recent years, in order to further improve the energy density of a supercapacitor to replace a lithium battery, researchers have introduced high-power-density carbon nanomaterials (carbon nanotubes, carbon nanofibers, graphene, and the like) and high-energy-density pseudocapacitive materials (such as transition metal oxide RuO)₂，TiO₂，MnO₂And Fe₃O₄And conductive organic matters and the like) to achieve the level of lithium batteries.

However, the carbon nanomaterial supercapacitor still has the problems of large energy storage attenuation due to high-speed charge/discharge and poor cycle stability, and particularly under high and low temperature conditions, the electrolyte convection impact and conductivity reduction are accelerated to deteriorate. Therefore, the development of pseudocapacitive materials with high conductivity and high mechanical strength is urgently needed.

Titanium carbide has excellent chemical stability, high hardness, excellent oxidation/corrosion resistance and good electrical conductivity (10)⁵-10⁶S/m, close to metal), becomes a potential candidate material for super capacitor electrodes,

the patent application CN110718402A discloses a flexible foldable super capacitor and a preparation method thereof, wherein a carbon nano tube macroscopic film is selected as a current collector, active substances are loaded on the surface of the current collector to construct a near-integrated composite electrode, the composite electrode is prepared by a coating method, electrostatic spinning, a liquid phase method and an electrochemical deposition method, and the active substances of the electrode adopt active carbon, graphene, conductive polymers and metal compounds; the metal compound includes titanium carbide; and then preparing the flexible foldable super capacitor through the processes of drying, cutting, welding, laminating, assembling, injecting liquid and packaging.

The method can take titanium carbide as an active substance, form slurry and then attach the slurry on the carbon nano tube macroscopic film. This structure is essentially a non-integral structure with adhesion. The structure is formed by bonding titanium carbide and a reinforcement body by conductive adhesive, and titanium carbide nano particles and the titanium carbide and the reinforcement body are connected by the adhesive, so that the transmission performance of ions between the particles and between a collector is greatly reduced; in addition, the cycle stability of the material is reduced due to the difference in the expansion coefficients of the phases.

Disclosure of Invention

The invention aims to overcome the defects of the conventional carbon nano material super capacitor, and provides an unbonded integrated titanium carbide material which is a titanium carbide nanotube and titanium carbide matrix integrated composite structure.

The inventors believe that the development of pseudocapacitive materials with high conductivity and high mechanical strength must be accompanied by high surface area to provide more active sites. Therefore, carbon nanotube films and similar structures are introduced into supercapacitor materials, however, in the prior art, pseudocapacitance nanomaterials are attached to the surfaces of the carbon nanotubes in the carbon nanotube films, the capacitance is rapidly reduced due to multiphase changes of the pseudocapacitance materials and structural deformation and even disintegration caused by the multiphase changes of the pseudocapacitance materials, and meanwhile, the bonding of the pseudocapacitance nanomaterials and carbon nanostructure interfaces is weakened, so that the charge transfer efficiency is reduced, and particularly under high and low temperature conditions, the electrolyte convection impact and the reduction of the conductivity are accelerated to be deteriorated, so that the cycling stability of electrode materials is poor. In order to promote rapid transfer of ions and increase in the transport speed of electrons, the inventors thought that a non-binding integral structure having a high surface area to provide more active sites and high mechanical strength was necessary to promote rapid transfer of ions and transport of electrons.

Based on the above conception, the inventor provides a preparation method of the unbonded integrated titanium carbide material.

The specific scheme is as follows:

a preparation method of an unbonded integrated titanium carbide material comprises the following steps:

(1) providing a carbon nanotube film;

(2) preparation of hydrated titanium/carbon nanotube film

Immersing the carbon nanotube film into a titanium source solution, performing electrochemical deposition, and drying a deposited sample to obtain a hydrated titanium/carbon nanotube film;

(3) preparation of titanium carbide nanotube film

Carrying out primary high-temperature heat treatment on the hydrated titanium/carbon nanotube film in a protective atmosphere to obtain a titanium carbide nanotube film;

(4) preparation of non-bonding integrated titanium carbide material

Embedding the titanium carbide nanotube film in graphite powder, and carrying out secondary high-temperature heat treatment in a protective atmosphere to obtain the unbonded integrated titanium carbide material.

Further, in the step (1), the thickness of the carbon nanotube film is 20-40 μm, and the specific surface area is 100-150m²g^-1。

Further, in the step (1), the carbon nanotube film is prepared by a floating catalyst chemical vapor deposition method, preferably, Ar/H₂Introducing mixed gas, introducing ethanol solution of 1-2% of ferrocene and 0.1-0.5% of thiophene at the volume fraction of 10-30 ml/h into a reactor at 1200-1300 ℃, and collecting layer by layer through a wheel rotating perpendicular to airflow to form a randomly oriented 20-40 mu m thick carbon nanotube film.

Further, in the step (2), the titanium source solution is a titanium salt aqueous solution, preferably TiCl₃Adjusting the pH of the aqueous solution to 1.0-2.0; optionally, the electrochemical deposition is performed for 400-1000 seconds at a constant potential of 0.5-1.0V; and drying the deposited sample at 60-100 ℃ for 24 hours under vacuum to obtain the hydrated titanium/carbon nanotube film.

Further, in the step (3), the temperature of the primary high-temperature heat treatment is 1200-1300 ℃, and the time is 5-10 hours; preferably, the primary high temperature heat treatment comprises: firstly, vacuumizing the reactor, then introducing protective atmosphere to atmospheric pressure, heating to 400-500 ℃ at the speed of 1-10 ℃/min, calcining for 1-2 hours at the temperature, heating to 1200-1300 ℃ at the speed of 1-10 ℃/min, and calcining for 5-10 hours at the temperature to obtain the titanium carbide nanotube film.

Further, in the step (4), the graphite powder is high-purity graphite powder with the size of 8000-10000 meshes;

optionally, the temperature of the secondary high-temperature heat treatment is 1200-1300 ℃, and the time is 10-15 hours; preferably, the secondary high temperature heat treatment includes: firstly, vacuumizing the reactor, then introducing protective atmosphere to atmospheric pressure, heating to 400-1300 ℃ at the temperature of 1-10 ℃/min, calcining for 1-2 hours, heating to 1200-1300 ℃ at the temperature of 1-10 ℃/min, and calcining for 10-15 hours at the temperature to obtain the unbonded integrated titanium carbide material.

The invention also protects the unbonded integrated titanium carbide material prepared by the preparation method of the unbonded integrated titanium carbide material.

Furthermore, the unbonded integrated titanium carbide material comprises two parts, namely a titanium carbide nanotube three-dimensional interconnection network and a titanium carbide nano layer, wherein the titanium carbide nanotube three-dimensional interconnection network is of an inner layer structure, the titanium carbide nano layer wraps the outside of the titanium carbide nanotube three-dimensional interconnection network, and the adjacent titanium carbide nano layers are interconnected.

The invention also protects an electrode comprising the unbonded integrated titanium carbide material.

The invention also protects a super capacitor comprising the electrode.

Has the advantages that:

in the invention, the method adopts the carbon nanotube film as the template to react with the electrodeposited titanium hydrate at high temperature, thereby solving the problem of incomplete reaction in the preparation of the titanium carbide nanotube by the current template method.

And moreover, the graphite particles are used as a carbon source, so that the preparation cost of the titanium carbide material is reduced, the regulation and control of the titanium carbide matrix structure are realized at high temperature, and the unbonded integrated titanium carbide material is obtained.

Further, the unbonded integrated titanium carbide material comprises two parts, namely a titanium carbide nanotube three-dimensional interconnection network and a titanium carbide nano layer, wherein the titanium carbide nanotube three-dimensional interconnection network is of an inner layer structure, the titanium carbide nano layer wraps the outside of the titanium carbide nanotube three-dimensional interconnection network, and the adjacent titanium carbide nano layers are interconnected. The titanium carbide nano-layered structure coats the titanium carbide nano-tubes and forms a dendritic three-dimensional interconnected structure bridging the titanium carbide nano-tubes inside, and finally the titanium carbide nano-tube reinforced titanium carbide nano-layered matrix integral composite material is formed. The layered structure of the material increases the specific surface area of the material, the large distance between layers and the strong interface bonding force between the inner titanium carbide nano tube and the outer titanium carbide nano layer, improves the ion transmission rate and the electron transfer rate, and realizes high electrochemical performance and cycling stability.

In a word, the unbonded integrated titanium carbide material has the advantages of high power density, high energy density and long cycle life, and under the condition of constant current of 2.0A/g, the capacitance is still kept above 86% after 15000 times of charging and discharging; the specific capacitance at 10A/g is 250-270F/g, and the method has wide application prospect in the field of super capacitors.

Drawings

In order to illustrate the technical solution of the present invention more clearly, the drawings will be briefly described below, and it is apparent that the drawings in the following description relate only to some embodiments of the present invention and are not intended to limit the present invention.

Fig. 1 is a scanning electron microscope image of a carbon nanotube film provided in an embodiment 1 of the present invention;

FIG. 2 is a scanning electron microscope image of a hydrated titanium/carbon nanotube film provided in example 1 of the present invention;

FIG. 3 is a scanning electron micrograph of a titanium carbide nanotube film according to an embodiment 1 of the present invention;

FIG. 4 is a scanning electron microscope image of an unbonded integrated titanium carbide material provided in embodiment 1 of the present invention;

fig. 5 is a cycle curve of the supercapacitor provided in one embodiment 2 of the present invention;

FIG. 6 is a charge-discharge curve at different current densities as provided in example 2 of the present invention;

FIG. 7 is one of the energy density and power density plots provided by the present invention;

FIG. 8 is a graph showing the charging and discharging curves at different current densities according to comparative example 2;

fig. 9 is a second graph of energy density and power density provided by the present invention.

Detailed Description

The definitions of some of the terms used in the present invention are given below, and other non-mentioned terms have definitions and meanings known in the art:

the method comprises the steps (1) to (4), wherein (2) and (4) are more critical. Specifically, the carbon nanotube film provided in step (1) may be a commercially available carbon nanotube film or may be prepared by itself. The carbon nanotube film is used as a template and a carbon source in the invention, preferably, the titanium carbide nanotube film has the thickness of 10-100 μm, the length and the width of the titanium carbide nanotube film reach the meter magnitude, and the titanium carbide nanotube film is a macroscopic film-shaped object formed by uniformly distributing titanium carbide nanotubes (microscopic) along each direction, the diameter of the microscopic titanium carbide nanotube film is 1-20nm, and the length of the microscopic titanium carbide nanotube film is 0.01-100 microns. More preferably, the carbon nanotube film has a thickness of 20-40 μm and a surface area of 100-150m²g^-1This can produce sufficient loaded active to provide high energy density.

The self-fabricating carbon nanotube film is preferably fabricated by a floating catalyst chemical vapor deposition process. Preferably, Ar/H is first reacted₂Introducing mixed gas into an ethanol solution containing ferrocene (volume fraction is 1-2%) and thiophene (volume fraction is 0.1-0.5%) to obtain mixed gas carrying catalyst ferrocene and carbon source ethanol, then introducing the mixed gas into a reactor at 1200-1300 ℃ at a flow rate of 10-30 ml/h, and collecting layer by layer through a wheel rotating perpendicular to airflow to form a randomly oriented 20-40 mu m thick carbon nanotube film. For example, Ar/H₂The flow ratio is 4:1-5:1, and the volume content of ferrocene is as follows: 1-2%, volume content of thiophene: 0.1-0.5%, Ar/H₂The flow rate of the mixed gas was 10-30 ml/h, and the reactor was stabilized at 1220-.

According to the method, the hydrated titanium/carbon nanotube film is prepared in the step (2), and aims to form a precursor of the titanium carbide nanotube film, the hydrated titanium/carbon nanotube film is obtained through electrochemical deposition, and the hydrated titanium is coated on the surface of the carbon nanotube film in a gel form.

Immersing the carbon nanotube film in a titanium source solution, preferably a titanium salt aqueous solution, such as 0.20-0.30mol/L TiCl₃Aqueous solution, then adjusting the pH value of the solution to 1.0-2.0 by using 6.0 mol/L hydrochloric acid, and carrying out 400-ion 1000-second electrochemical deposition under the constant potential of 0.5-1.0V; more preferably, the electrochemical deposition is carried out for 450-650 seconds under the constant potential of 0.5-0.8V, and the titanium/carbon nanotube hydrate film is obtained.

According to the method, the titanium carbide nanotube film is prepared in the step (3), the conventional titanium carbide nanosheet is of a two-dimensional structure, the flaky materials are dispersed, and the strength is low. Specifically, the titanium carbide nanotube film is subjected to high-temperature treatment in a protective atmosphere to perform a carbonization reaction, and has the characteristics of high strength and high conductivity, which are not possessed by the existing titanium carbide materials. The protective atmosphere may be an inert gas, such as at least one of nitrogen and a gas of an element belonging to group zero of the periodic table, which is known to those skilled in the art and will not be described herein. Preferably, the temperature of the primary high-temperature heat treatment is 1200-1300 ℃, and the time is 5-10 hours; more preferably, the primary high temperature heat treatment comprises: firstly, vacuumizing the reactor, then introducing protective atmosphere to atmospheric pressure, heating to 400-500 ℃ at the speed of 1-10 ℃/min, calcining for 1-2 hours at the temperature, heating to 1200-1300 ℃ at the speed of 1-10 ℃/min, and calcining for 5-10 hours at the temperature to obtain the titanium carbide nanotube film. The titanium oxide nano structure can be generated by calcining for 1-2 hours at low temperature, thereby providing a material base for controlling the reaction uniformity of the titanium oxide and the carbon.

According to the invention, the titanium carbide nanotube film obtained in the step (3) has the problem of low electrochemical performance, so that the titanium carbide nanotube film is not suitable for being directly used as an electrode. Preferably, the purity of the graphite powder is more than 99.99wt%, and the particle size is 8000-10000 meshes.

The temperature of the secondary high-temperature heat treatment is 1200-1300 ℃, and the time is 10-15 hours; more preferably, the secondary high temperature heat treatment includes: firstly, vacuumizing the reactor, then introducing protective atmosphere to atmospheric pressure, heating to 400-minus-one temperature 500 ℃ at the speed of 1-10 ℃/min, calcining for 1-2 hours at the temperature, heating to 1200-minus-one temperature 1300 ℃ at the speed of 1-10 ℃/min, calcining for 10-15 hours at the temperature, and repeating the process for 3-5 times to obtain the unbonded integrated titanium carbide material.

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available. In the following examples, "%" means weight percent, unless otherwise specified.

Example 1

The preparation method of the unbonded integrated titanium carbide material comprises the following steps:

(1) preparation of carbon nanotube film

The carbon nanotube film is prepared by a floating catalyst chemical vapor deposition method. Firstly, Ar/H₂Introducing the mixed gas carrying ethanol raw material containing 1.5% of ferrocene and 0.5% of thiophene into a 1300 ℃ reactor at the speed of 10 ml/h; the carbon nanotubes were then collected layer by a wheel rotating perpendicular to the gas flow to form a randomly oriented 20 μm thick carbon nanotube film.

The scanning electron micrograph of the obtained carbon nanotube film is shown in fig. 1, from which it can be seen that the carbon nanotubes are uniformly distributed to form the carbon nanotube film, which shows the initial shape of a three-dimensional network.

(2) Preparation of hydrated titanium/carbon nanotube film

First, 0.20 mol/L TiCl is prepared₃Aqueous solution, pH of solution is adjusted to 2.0 by 6.0 mol/L hydrochloric acid; then, taking the carbon nanotube film, the platinum sheet and Ag/AgCl as a working electrode, a counter electrode and a reference electrode respectively, and carrying out electrochemical deposition for 500 seconds in a three-electrode system under a constant potential of 0.5V; the deposited sample was dried in vacuum at 60-100 ℃ for 24 hours.

The scanning electron micrograph of the obtained titanium hydrate/carbon nanotube film is shown in fig. 2, and titanium hydrate is uniformly coated on the surfaces of the carbon nanotubes and is completely filled between the carbon nanotubes to form a structure in which the carbon nanotubes are inserted in the middle of the titanium hydrate layer.

(3) Preparation of titanium carbide nanotube film

Carrying out high-temperature heat treatment on the hydrated titanium/carbon nanotube film treated in the step (2) at 1300 ℃ in an argon atmosphere, and specifically comprising the following steps: vacuumizing the reactor (less than 10 Pa), introducing high-purity argon (more than or equal to 99.999%) to one atmosphere, heating to 400 ℃ at the temperature of 5 ℃/min, preserving the heat for 1 hour, heating to 1300 ℃ at the temperature of 5 ℃/min, and preserving the heat for 10 hours at the temperature to obtain the titanium carbide nanotube film.

The scanning electron micrograph of the obtained titanium carbide nanotube film is shown in fig. 3, from which it can be seen that in the macroscopic tube film, many titanium carbide nanotubes are uniformly distributed and the structure of the carbon nanotube template presented in fig. 1 and 2 is maintained.

(4) Densification of titanium carbide nanotubes reinforced titanium carbide substrates

And (3) repeating the step (3) on the titanium carbide nanotube film treated in the step (3), namely, embedding the hydrated titanium/titanium carbide nanotube film in 8000-mesh high-purity graphite powder, and performing high-temperature heat treatment in an argon atmosphere at 1300 ℃, specifically comprising the following steps: firstly, vacuumizing (less than 10 Pa) in a reactor, then introducing high-purity argon (more than or equal to 99.999%) to atmospheric pressure, heating to 400-plus-500 ℃ at the speed of 5 ℃/min, preserving the heat for 1-2 hours at the temperature, heating to 1200-plus-1300 ℃ at the speed of 5 ℃/min, and preserving the heat for 10-15 hours at the temperature to obtain the unbonded integrated titanium carbide material.

The scanning electron micrograph of the obtained unbonded integrated titanium carbide material is shown in fig. 4, and it can be seen that the external part presents a layered structure, and adjacent layered structures are interconnected, namely a titanium carbide nano layer; as can be known from FIG. 3, the interior of the titanium carbide nanotube is a three-dimensional network structure, i.e., a three-dimensional interconnected network of titanium carbide nanotubes. The bonding size can be known that a single titanium carbide nanolayer may contain 1, 2 or more three-dimensional interconnected networks of titanium carbide nanotubes.

Example 2

The unbonded integrated titanium carbide material prepared in the example 1 is used as an electrode, and 1.0 mol/L sulfuric acid is used as an electrolyte to form a symmetrical supercapacitor. The symmetrical super capacitor is characterized in that the two electrodes have the same composition and the same electrode reaction, the reaction directions are opposite, and the assembly of the symmetrical super capacitor adopts the prior art.

The obtained symmetrical super capacitor is subjected to charge and discharge tests, and the capacitance is still maintained to be more than 86% after 15000 times of charge and discharge under the constant current condition of 2.0A/g, as shown in figure 5, and the high cycle stability is shown. The test was performed at different scan rates and found to be at 25 mV. s^-1The specific capacitance of the capacitor is up to 375F g^-1Above, and at 4000mV · s^-1The specific capacitance is still as high as 221F g^-1As shown in fig. 6. FIG. 7 shows the results of energy density and power density tests, the energy density and power density of the unbonded integrated titanium carbide material prepared in example 1 are respectively as high as 64 Wh-kg^-1And 9.5 kW. kg-1.

Comparative example 1

The titanium carbide nanotube film obtained in example 1 was used as an electrode, and an electrochemical test was conducted with reference to example 2, and it was found that the concentration was 25mV s^-1Specific capacitance of only 181F g^-1At 4000mV · s^-1Specific time capacitance of only 34F g^-1As shown in fig. 6. FIG. 7 shows the results of measuring the energy density and the power density of the titanium carbide nanotube film prepared in example 1, which were 15 Wh kg in terms of energy density and power density, respectively^-1And 1.1 kW kg-1. This shows that on the basis of titanium carbide nanotube film, titanium carbide nanolayers are grown to realize interconnection and form a matrix, and the specific capacitance, energy density and power density of the material can be greatly improved.

Comparative example 2

Commercially available titanium carbide nanosheets (with a plate diameter of 0.1-1 μm and a thickness of 100-200 nm), carbon nanotubes (with a diameter of 10-20nm and a length of 5-15 μm) and polyvinylidene fluoride were dispersed in N-methyl-2-pyrrolidone in a mass ratio of 8:1:1, spin-coated to form a film of about 40 μm on the surface of stainless steel, and then dried at 80 ℃ in vacuum for 24 hours to prepare a symmetric supercapacitor according to example 2.

Found at 25 mV. s^-1Specific capacitance of 275F g^-1And at 4000mV s^-1The specific capacitance is 62F g^-1As shown in fig. 8. As shown in FIG. 9, the energy density and power density of the titanium carbide nanosheet/carbon nanotube electrode were measured to be 19 Wh-kg^-1And 1.5 kW. kg-1. This shows that the material combining the conventional titanium carbide nanosheets and the carbon nanotubes is general in specific capacitance, energy density and power density and does not have the advantages of the material prepared by the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.