Preparation method of supercapacitor electrode material

Abstract

The application discloses a preparation method of a supercapacitor electrode material, and belongs to the field of supercapacitors. The preparation method of the supercapacitor electrode material comprises the following steps: S1, mixing LiF with 9M hydrochloric acid, heating and stirring in an oil bath, and then adding a MAX material, magnetically stirring and reacting; S2, centrifuging the mixed solution obtained in S1, and adding a mixed solution of LiCl and deionized water, and then centrifuging after standing; S3, after centrifugation is completed, freeze-drying the sample to obtain MXene; S4, dissolving the MXene in deionized water, and then performing membrane formation by means of suction filtration after complete mixing, obtaining an MXene film, and performing drying treatment; and S5, placing the MXene film in a joule heating heater to obtain a TiO2-MXene composite material.

Description

Technical Field

[0001] This invention belongs to the field of supercapacitors, and specifically relates to a method for preparing supercapacitor electrode materials. Background Technology

[0002] Supercapacitors are a new type of energy storage device developed in recent years. They possess outstanding advantages, including energy densities unmatched by traditional capacitors and higher power densities than lead-acid batteries, thus attracting widespread attention and research. Furthermore, supercapacitors feature low maintenance costs, excellent cycle stability, high safety, and high charge / discharge rates, making them an ideal green energy storage device. Electrode materials are a key factor determining the electrical performance of supercapacitors. Current research on electrode materials mainly includes carbon-based materials, transition metal oxides, conductive polymers, and composite materials (including alloys). Although supercapacitors possess advantages such as high power density, fast charge / discharge rates, and high plasticity, their energy density remains relatively low, which is a key factor currently limiting their widespread application. Therefore, developing electrode materials with high specific area and high specific capacitance is one of the challenges in improving the performance of supercapacitors. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing supercapacitor electrode materials, thereby solving the problems in the prior art.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A method for preparing a supercapacitor electrode material, wherein the electrode material is a TiO2-MXene composite material, and the preparation steps include:

[0006] S1, after mixing LiF with 9M hydrochloric acid, heat and stir in an oil bath, then add MAX material, stir magnetically and react;

[0007] S2, the mixed solution obtained from S1 is centrifuged, and a mixed solution of LiCl and deionized water is added, and after standing, it is centrifuged again;

[0008] S3, After centrifugation, the sample was freeze-dried to obtain MXene;

[0009] S4. Dissolve MXene in deionized water, and after complete mixing, filter to form a membrane to obtain an MXene membrane, which is then dried.

[0010] S5, the MXene film is placed in a Joule heater and heated to obtain TiO2-MXene composite material.

[0011] Furthermore, the mass ratio of LiF, MAX, and LiCl is 1:1:(1-3).

[0012] Further, in S1, LiF is mixed with 9M hydrochloric acid and then heated in an oil bath at 38-42°C and stirred for 5-10 minutes.

[0013] Furthermore, the parameters for magnetic stirring in S1 are: rotation speed 20 rad / s, temperature 42℃, and reaction time 24 h after stirring.

[0014] Furthermore, in S2, the mixed solution obtained in S1 is first centrifuged 4-6 times. After adding LiCl and deionized water, it is allowed to stand for 30 minutes and then centrifuged 6 times.

[0015] Further, in S4, the MXene membrane is placed in a Joule heater and heated at 1200-1400°C for 10-20 seconds.

[0016] A supercapacitor electrode material is prepared by the above method.

[0017] Application of TiO2-MXene composite materials in the manufacture of supercapacitors.

[0018] Furthermore, the TiO2-MXene composite material is used as an electrode in a supercapacitor.

[0019] The beneficial effects of this invention are:

[0020] 1. In this invention, titanium dioxide (TiO2) particles are grown in situ on the surface of MXene using a Joule heating apparatus, and the entire preparation process is short.

[0021] 2. The composite material prepared in this invention, as an electrode material for supercapacitors, has the characteristics of high area ratio and high capacitance ratio, which can effectively improve the energy density of supercapacitors, while also reducing the volume and weight of supercapacitors. Attached Figure Description

[0022] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a scanning electron microscope image of the TiO2-MXene composite material of the present invention;

[0024] Figure 2 This is the structural characterization (XRD) diagram of Embodiment 1 of the present invention;

[0025] Figure 3 This is the cyclic voltammetry (CV) plot of Example 1 of the present invention at a scan rate of 20 mV / s;

[0026] Figure 4 This is the cyclic voltammetry (CV) plot of Example 1 of the present invention at a scan rate of 50 mV / s;

[0027] Figure 5 This is the cyclic voltammetry (CV) plot of Example 2 of the present invention at a scan rate of 20 mV / s;

[0028] Figure 6 This is the cyclic voltammetry (CV) plot of Example 2 of the present invention at a scan rate of 50 mV / s. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] A supercapacitor electrode material is composed of titanium dioxide and MXene, and its electron micrograph is shown below. Figure 1 As shown;

[0031] Example 1

[0032] The preparation method of supercapacitor electrode material includes the following steps:

[0033] S1, weigh 1g LiF, measure 20ml 9M hydrochloric acid, mix and stir in a 38℃ oil bath for 5 minutes, then add 1g MAX material, adjust to a speed of 20rad / s, magnetically stir at 42℃, and react for 24h.

[0034] S2, after centrifuging 4 times, add a mixed solution of 1g LiCl and 20ml deionized water to the centrifuge tube, let it stand for 30 minutes, and then centrifuge 6 more times.

[0035] S3. After centrifugation, the sample was freeze-dried for 12 hours to obtain the MXene product.

[0036] S4. Weigh 0.1g of dried MXene and dissolve it in 100ml of deionized water. After complete mixing, filter the mixture to form a membrane. Place the membrane in a vacuum drying oven and dry for 12h to obtain the MXene film.

[0037] S5. Place the MXene film in a Joule heater and heat it at 1200℃ for 10 seconds to obtain the TiO2-MXene composite material.

[0038] Example 2

[0039] The preparation method of supercapacitor electrode material includes the following steps:

[0040] S1, weigh 1g LiF, measure 20ml 9M hydrochloric acid, mix and stir in an oil bath at 42℃ for 10 minutes, then add 1g MAX material, adjust to a speed of 20rad / s, magnetically stir at 42℃, and react for 24h.

[0041] S2, after centrifuging 6 times, add a mixed solution of 3g LiCl and 10ml deionized water to the centrifuge tube, let it stand for 30 minutes, and then centrifuge 6 more times.

[0042] S3. After centrifugation, freeze-dry the sample for 12 hours.

[0043] S4. Weigh 0.1g of dried MXene and dissolve it in 100ml of deionized water. After complete mixing, filter the mixture to form a membrane. Place the membrane in a vacuum drying oven and dry for 12h to obtain the MXene product.

[0044] S5. Place the MXene film in a Joule heater and heat it at 1400℃ for 10 seconds to obtain the TiO2-MXene composite material.

[0045] The TiO2-MXene composite materials prepared in Examples 1 and 2, as well as conventional electrode materials, were used as electrodes for the supercapacitors to test their performance.

[0046] Cyclic voltammetry was used for testing. The prepared TiO2-MXene composite material was mixed with a conductive agent and polyvinylidene fluoride (PVDF) at a weight ratio of 8:1:1, using ethanol as a solvent. After stirring for 6 hours, the mixture was uniformly coated onto carbon paper, vacuum dried at 110°C, and pressed into a sheet to obtain the working electrode. The electrolyte was 6M KOH. The separator was a cellulose acetate membrane. After assembly and activation for 12 hours, measurements were taken to ensure sufficient electrolyte wetting of the electrode. Battery testing was conducted on a CHI640 electrochemical workstation using cyclic voltammetry, with a voltage range of 0.00–1.00 V. The CV curve for Example 1 is shown below. Figure 3 As shown in Figure 4, the CV diagram of Example 2 is as follows. Figure 5 As shown in Figure 6.

[0047] like Figure 3 As shown in Figure 4, at scan rates of 20 mV / s and 50 mV / s, the capacitance of the TiO2-MXene composite material prepared in Example 1 was higher than that of ordinary activated carbon materials. Figure 5 As shown in Figure 6, at scan rates of 20 mV / s and 50 mV / s, the capacitance of the TiO2-MXene composite material prepared in Example 2 was also higher than that of ordinary activated carbon material.

[0048] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for preparing a supercapacitor electrode material, characterized in that, The electrode material is a TiO2-MXene composite material, and the preparation steps include: S1. After mixing LiF with 9M hydrochloric acid, heat and stir in an oil bath, then add MAX material, stir magnetically and react. S2. Centrifuge the mixed solution obtained in S1, add a mixed solution of LiCl and deionized water, let it stand, and then centrifuge again. S3. After centrifugation, the sample is freeze-dried to obtain MXene; S4. Dissolve MXene in deionized water, and after complete mixing, filter to form a membrane to obtain an MXene membrane, and then dry it. S5 and MXene films are placed in a Joule heater and heated at 1200-1400℃ for 10-20 seconds to obtain TiO2-MXene composite material.

2. The method for preparing a supercapacitor electrode material according to claim 1, characterized in that, The mass ratio of LiF, MAX and LiCl is 1:1:(1-3).

3. The method for preparing a supercapacitor electrode material according to claim 1, characterized in that, In S1, LiF is mixed with 9M hydrochloric acid, and then heated in an oil bath at 38-42℃ with stirring for 5-10 minutes.

4. The method for preparing a supercapacitor electrode material according to claim 1, characterized in that, The parameters for magnetic stirring in S1 are: rotation speed 20 rad / s, temperature 42℃, and reaction time 24 h after stirring.

5. The method for preparing a supercapacitor electrode material according to claim 1, characterized in that, In S2, the mixed solution obtained in S1 is first centrifuged 4-6 times. After adding LiCl and deionized water, it is allowed to stand for 30 minutes and then centrifuged 6 times.

6. A supercapacitor electrode material, prepared by the method described in any one of claims 1-5.

7. The application of TiO2-MXene composite material prepared by the method for preparing a supercapacitor electrode material as described in any one of claims 1-5 in the manufacture of supercapacitors.

8. The application according to claim 7, characterized in that, The TiO2-MXene composite material is used as the electrode of the supercapacitor.

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