Preparation method of MXene / polyaniline composite membrane electrode

Abstract

The invention discloses a preparation method of an MXene / polyaniline composite membrane electrode, which comprises the following steps: electroplating polyaniline on the surface of an MXene film at a certain temperature to obtain a brand new composite membrane material. The method specifically comprises the following steps: mixing lithium fluoride and hydrochloric acid according to a certain proportion, and then etching an MAX phase to obtain a mixture; carrying out ultrasonic centrifugal cleaning on the MXene membrane and then carrying out vacuum filtration to obtain an MXene membrane; and electroplating polyaniline on the surface of the MXene film through an electrochemical workstation by using an aniline sulfate mixture as an electrolyte, using the obtained MXene film as a working electrode, using a platinum sheet as a counter electrode and using Ag / AgCl as a reference electrode, and finally obtaining the MXene / polyaniline composite film electrode. The method is simple to operate and has the potential of large-scale production, and the obtained membrane electrode not only has good conductivity, but also has complete lithium ion reversibility, can be suitable for the field of all-solid-state battery energy storage, and has wide market prospects.

Description

Technical Field

[0001] The invention relates to a method for preparing a MXene / polyaniline composite membrane electrode, and in particular to a method for preparing a MXene / polyaniline composite diaphragm electrode, and belongs to the field of electrode materials and solid-state energy storage batteries. Background Art

[0002] As the global consumption of lithium mineral resources becomes increasingly intense and the safety issues caused by non-solid-state lithium-ion batteries become increasingly prominent, the development of the next generation of energy storage devices is imminent, but many scientific problems still exist, which seriously affect the large-scale commercial application of all-solid-state energy storage devices. Polyaniline has been widely used in the field of electrochemical energy storage due to its high charge storage capacity and good electrochemical performance. In addition, a graphene-like two-dimensional nanomaterial, MXene, has become increasingly prominent in the field of electrochemical energy storage due to its rich surface groups and excellent conductivity. Therefore, it is of great significance in the field of electrochemical energy storage to combine the two and develop a composite membrane electrode material that can retain the advantages of both materials. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a MXene / polyaniline composite film electrode that is simple to operate and highly repeatable. In order to electroplate and grow polyaniline on the surface of MXene, the present invention adopts the following technical scheme: A method for preparing a MXene / polyaniline composite membrane electrode material comprises the following steps: (1) Take an appropriate amount of MAX phase, hydrochloric acid, and lithium fluoride salt, mix them, react at a certain temperature, centrifuge, wash, and dry to obtain multilayer MXene; (2) ultrasonically exfoliating the multilayer MXene in step (1) to obtain a single-layer MXene nanosheet colloid, vacuum filtering the MXene nanosheet colloid, and drying to obtain a MXene membrane; (3) Mix appropriate amounts of sulfuric acid and aniline monomer and stir thoroughly until transparent light yellow without flocs to obtain an electroplating solution; (4) Using the MXene film in step (2) as the working electrode, the electroplating solution in step (3) as the electrolyte, the platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode, electroplating polyaniline on the MXene film in a three-electrode system using an electrochemical workstation and a transverse current method or a constant potential method, and then washing and drying to obtain the MXene / polyaniline composite film electrode.

[0004] In step (1), the concentration of hydrochloric acid includes but is not limited to 6-9 mol / L, the ratio of MAX phase raw material, acid and lithium fluoride salt includes but is not limited to 1-2 g: 20-40 mL: 0.62-1.24 g, the reaction temperature is 35° C., and the reaction time includes but is not limited to 24-48 h.

[0005] The thickness of the filtered MXene film in step (2) includes but is not limited to 500-1000 nm.

[0006] The concentration of sulfuric acid in step (3) includes but is not limited to 1-2 mol / L, and the molar ratio of acid to aniline monomer includes but is not limited to 4:1.

[0007] The current used in the constant current method in step (4) includes but is not limited to 0.1-0.3 mA / s, and the electroplating time includes but is not limited to 180-360 s; the voltage used in the constant voltage method includes but is not limited to 0.85 V-1.20 V, and the electroplating time includes but is not limited to 60-180 s.

[0008] The MXene / polyaniline composite membrane electrode material is obtained by the preparation method.

[0009] Beneficial effects of the present invention: The MXene / polyaniline composite membrane electrode prepared by the present invention is a brand-new electrode material. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 SEM image of the surface of MXene / polyaniline composite membrane electrode material obtained in Example 1 Figure 2 SEM image of the pure MXene film surface before electroplating experiment DETAILED DESCRIPTION

[0011] The present invention will be further described below in conjunction with specific examples. It should be understood that the following examples are only for The present invention is not intended to limit the scope of the present invention. Some non-essential improvements and adjustments are made to the contents of the above invention.

[0012] Example 1 Preparation of MXene / polyaniline composite film electrode: (1) Preparation of multilayer MXene: 1.06 g LiF was added to 20 mL 6 mol / L hydrochloric acid and stirred at 35 °C for 5 min until LiF was completely dissolved. Then 1.0 g MAX phase raw material (Ti3AlC2) was added to the mixed solution and the reaction was continued with stirring for 24 h. The suspension after the reaction was washed with deionized water by centrifugation several times until the pH value was 6-7 and dried to obtain multilayer MXene powder.

[0013] (2) Preparation of MXene membrane: Take 0.5 g of the multilayer MXene powder obtained above and add 100 mL of deionized water. Then, ultrasonically disperse it in an ice-water bath for 60 minutes. Then, centrifuge the obtained suspension at 3500 rpm for 60 minutes. Take the upper colloidal solution and vacuum filter it on a hydrophobic filter membrane. After drying, the MXene membrane is obtained.

[0014] (3) Electropolymerization of polyaniline on MXene film: Add 2.3 g of aniline monomer into 50 mL of 2 mol / L sulfuric acid and stir for 30 min to fully dissolve it, then use it as the electrolyte. Use the MXene film described in step (2) as the working electrode, Ag / AgCl as the reference electrode, and platinum sheet as the counter electrode. Electroplating is performed for 120 s using a constant potential method (1.2 V). Then, the electroplated film is washed with ethanol and deionized water, respectively, to obtain a MXene / polyaniline composite film electrode.

[0015] Figure 1 This is the SEM image of the surface of the MXene / polyaniline composite membrane electrode material of Example 1.

[0016] The above embodiments are merely examples of the present invention. Although the best embodiments and drawings of the present invention are disclosed for illustrative purposes, the present invention is not limited to the above embodiments. Any person skilled in the art may make various substitutions, changes and modifications without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the contents disclosed in the best embodiments and drawings.

Claims

1. A method for preparing a MXene / polyaniline composite membrane electrode, characterized in that: The following steps are involved: (1) Take appropriate amount of MAX phase, hydrochloric acid and lithium fluoride salt, mix them, react at a certain temperature, centrifuge and wash them, and dry them to obtain multilayer MXene; (2) Take the multilayer MXene in step (1) and ultrasonically peel off to obtain a single-layer MXene nanosheet colloid, vacuum filter the MXene nanosheet colloid, and dry it to obtain a MXene film; (3) Mix appropriate amount of sulfuric acid and aniline monomer and stir them until transparent light yellow without flocs to obtain an electroplating solution; (4) Use the MXene film in step (2) as the working electrode, the electroplating solution in step (3) as the electrolyte, the platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode, use an electrochemical workstation, adopt a transverse current method or a constant potential method, and electroplate polyaniline on the MXene film in a three-electrode system, and wash and dry it to obtain the MXene / polyaniline composite film electrode.

2. The method for preparing a MXene / polyaniline composite film according to claim 1, wherein: In step (1), the acid concentration includes but is not limited to 6-9 mol / L, the ratio of MAX phase raw material, acid and lithium fluoride salt includes but is not limited to 1-2 g: 20-40 mL: 0.62-1.24 g, the reaction temperature is 35° C., and the reaction time includes but is not limited to 24-48 h.

3. The method for preparing the MXene / polyaniline composite membrane electrode according to claim 1, characterized in that: In step (2), the ultrasonic exfoliation is performed at 0-4° C. for 1-2 hours, and the thickness of the MXene film obtained by vacuum filtration includes but is not limited to 0.8-1.2 μm.

4. The method for preparing the MXene / polyaniline composite membrane electrode according to claim 1, characterized in that: In step (3), the concentration of sulfuric acid includes but is not limited to 1-2 mol / L, and the molar ratio of acid to aniline monomer includes but is not limited to 4:

1.

5. The method for preparing the MXene / polyaniline composite membrane electrode according to claim 1, characterized in that: In step (4), the current used in the constant current method includes but is not limited to 0.1-0.3 mA / s, and the electroplating time includes but is not limited to 180-360 s; the voltage used in the constant voltage method includes but is not limited to 0.85 V-1.20 V, and the electroplating time includes but is not limited to 60-180 s.

Images