A conductive polymer-siloxane composite material, its preparation method and application

Abstract

This invention discloses a conductive polymer-siloxane composite material, its preparation method, and its applications. The conductive polymer-siloxane composite material mainly consists of siloxane nanosheets and a conductive polymer coated on the surface of the siloxane nanosheets. The preparation method includes etching CaSi2 with hydrochloric acid to prepare siloxane nanosheets, mixing the siloxane nanosheets, dopant, and conductive polymer monomer solution, adding an oxidant, and cleaning and drying. The resulting conductive polymer-siloxane composite material is used to prepare electrode materials for energy storage devices. The method of this invention is simple and low-cost, and the obtained conductive polymer-siloxane composite material has high conductivity and a large specific surface area, making it suitable as an electrode material for energy storage devices and exhibiting excellent electrochemical performance.

Description

Technical Field

[0001] This invention relates to a composite material, its preparation method, and its application in the field of composite electrode material preparation technology, and particularly to a conductive polymer-siloxane composite material, its preparation method, and its application. Background Technology

[0002] With the rapid development of portable electronic devices, electric vehicles, smart grids, and other fields, improving the electrochemical performance of existing electrochemical energy storage devices and designing novel energy storage devices have become two major research hotspots. The development of electrode materials is an important research approach to achieving these goals.

[0003] Siloxenes are novel silicon-based two-dimensional materials. Three possible planar structural types of siloxenes have been reported in the literature: Weiss-type, Kautsky-type, and chain-like siloxenes. In the field of energy storage, siloxenes have proven to be excellent electrode materials for energy storage devices, exhibiting good cycle stability. Compared with other two-dimensional materials, siloxenes have the advantages of simple synthesis methods and low cost. However, their poor electronic conductivity and small specific surface area due to the large number of oxygen-containing functional groups still limit their application in the electrodes of energy storage devices.

[0004] Conductive polymers, also known as conductive high-performance polymers, are polymers with highly π-π conjugated polymer chains. Conductive polymers possess unique electrical and optical properties similar to inorganic semiconductors, and are environmentally stable and inexpensive, giving them significant advantages in practical applications in energy storage. However, in supercapacitors, they provide pseudocapacitive specific capacitance, resulting in poor cycle stability. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a conductive polymer-siloxane composite material, its preparation method, and its application.

[0006] The technical solution adopted in this invention is as follows:

[0007] I. A conductive polymer-siloxane composite material:

[0008] The conductive polymer-siloxane composite material has a transverse dimension of 0.1–100 μm, a longitudinal dimension of less than 200 nm, and a conductivity greater than 0.1 S / cm. The conductive polymer-siloxane composite material includes siloxane nanosheets and a conductive polymer layer coated on the surface of the siloxane nanosheets. The conductive polymer layer coats the surface of the siloxane nanosheets, and may completely or partially coat the siloxane nanosheets. The conductive polymer layer has a dense or porous structure, including a porous structure. The thickness of the conductive polymer layer in the conductive polymer-siloxane composite material is less than 100 nm. The conductive polymer layer is made using conductive polymer nanomaterials, which may be one of nanoparticles, nanofibers, nanorods, nanosheets, or nanofilms.

[0009] The conductive polymer layer is one or more of polypyrrole, polyaniline, polythiophene, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), and polyacetylene.

[0010] II. A method for preparing a conductive polymer-siloxane composite material, comprising the following steps:

[0011] Step 1) Preparation of siloxane nanosheets: Under the temperature conditions of -30 to 5℃, 1g of calcium silicide CaSi2 is added to 100 to 1000mL of hydrochloric acid solution and reacted for 10 to 200h. After the reaction is completed, the product is washed with acetone and water until neutral, filtered and freeze-dried to obtain siloxane nanosheets.

[0012] Step 2) Preparation of mixed solution: Dissolve the conductive polymer monomer in a sufficient amount of solvent to obtain a conductive polymer monomer solution. Disperse the siloxane nanosheets obtained in step 1) in the conductive polymer monomer solution and mix the solution evenly using ultrasonic mixing to obtain a mixed solution.

[0013] The solvent used is water or ethanol.

[0014] Step 3) Place the mixed solution on a magnetic stirring table, and add the oxidant dropwise to the mixed solution at a reaction temperature of 0-25°C and react for 1-24 hours to obtain the conductive polymer-siloxane composite material.

[0015] The conductive polymer monomers in the mixed solution will undergo a polymerization reaction with the oxidant to form a conductive polymer layer on the surface of the siloxane nanosheets.

[0016] Step 4) Clean the conductive polymer-siloxane composite material obtained in step 3) with alcohol and water in sequence, and then place the cleaned conductive polymer-siloxane composite material in an oven at 50-100℃ to dry it, so as to obtain the final conductive polymer-siloxane composite material.

[0017] In step 1), the concentration of the hydrochloric acid solution is 0.05–11.8 mol / L, and the freeze-drying temperature is -50–-30°C.

[0018] In step 2), the mass ratio of the conductive polymer monomer to the siloxane nanosheet is 1:50 to 5:1. The conductive polymer monomer is one or more of pyrrole, aniline, thiophene, 3,4-ethylenedioxythiophene-styrene sulfonic acid, and acetylene.

[0019] The mixed solution in step 2) may also contain a dopant, wherein the molar mass ratio of the conductive polymer monomer to the dopant is 100:1 to 2:1, and the dopant is one of protic acid, halogen, sulfonate, and sulfate.

[0020] Dopants can be added to the mixed solution to enhance the conductivity of the conductive polymer.

[0021] In step 3), the molar mass ratio of the conductive polymer monomer to the oxidant is 1:1 to 1:3, and the oxidant is one or more of ferric chloride, potassium permanganate, sodium persulfate, ferric sulfate, ammonium persulfate, hydrogen peroxide, potassium dichromate, potassium iodate, and benzoyl peroxide.

[0022] The oxidant is added at a rate of 0.1–50 ml / min in step 3).

[0023] The protic acid is hydrochloric acid, nitric acid, sulfuric acid, perchloric acid, phosphoric acid, p-toluenesulfonic acid, benzenesulfonic acid, or acetic acid; the halogen is iodine or bromine; the sulfonate is one of sodium lignosulfonate, sodium p-aminobenzenesulfonate, sodium anthraquinone-2-sulfonate, sodium 2,7-naphthalenedisulfonate, sodium dodecylbenzenesulfonate, sodium p-methylbenzenesulfonate, sodium dodecylsulfonate, or sodium toluenesulfonate; the sulfate is one of zinc sulfate, cerium sulfate, nickel sulfate, magnesium sulfate, ammonium sulfate, sodium sulfate, stannous sulfate, sodium dodecyl sulfate, or potassium sulfate.

[0024] III. Applications of conductive polymer-siloxane composite materials:

[0025] The conductive polymer-siloxane composite material is used as an electrode material for energy storage devices, including lithium batteries, supercapacitors, and zinc batteries.

[0026] This invention discloses a conductive polymer-siloxane composite material, its preparation method, and its applications. The conductive polymer-siloxane composite material consists of siloxane nanosheets coated with a conductive polymer. The preparation method includes etching CaSi2 with hydrochloric acid to prepare siloxane nanosheets, mixing the siloxane nanosheets with a monomer solution, adding an oxidant, and then cleaning and drying. The method of this invention is simple, low-cost, and yields a conductive polymer-siloxane composite material with high conductivity and a large specific surface area. It can be used as an electrode material for energy storage devices and exhibits excellent electrochemical performance.

[0027] The beneficial effects of this invention are as follows:

[0028] 1. The conductive polymer-siloxane composite material successfully prepared by this invention is simple and readily available, cost-controllable, has a simple and repeatable process, and is highly operable.

[0029] 2. The conductive polymer-siloxane composite material successfully prepared by this invention has significantly improved specific surface area and porosity, improving the wettability of electrolytes and making it suitable for use as an electrode material in energy storage devices. Thanks to this two-dimensional porous structure, the electrode sheets using this material have excellent cycle stability and significantly improved overall performance.

[0030] 3. Compared to silicon oxide nanosheets, the conductive polymer-siloxane composite material prepared in this invention exhibits significantly improved electrical conductivity, which facilitates electron transport and also improves electrochemical performance. Furthermore, compared to conductive polymer materials, the conductive polymer-siloxane composite material enhances the stability of electrode cycling. Therefore, the conductive polymer-siloxane composite material is an ideal material for electrodes in energy storage devices. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the process for preparing the polypyrrole-siloxane composite material in Example 1;

[0032] Figure 2 This is an electron microscope image of the siloxane nanosheets used in Example 1;

[0033] Figure 3 This is an electron microscope image of the polypyrrole-siloxane composite material prepared in Example 1;

[0034] Figure 4 These are conductivity test graphs of the conductive polymer-siloxane composite materials prepared in Examples 1-3;

[0035] Figure 5 The image shows the cyclic voltammogram of the polypyrrole-siloxane composite electrode prepared in Example 1 at a scan rate of 50 mV / s.

[0036] Figure 6The graph shows the constant current charge-discharge of the polypyrrole-siloxane composite electrode sheet prepared in Example 1 at a current density of 0.01 A / g.

[0037] Figure 7 This is an electron microscope image of the polyaniline-siloxane composite material prepared in Example 2;

[0038] Figure 8 The polyaniline-siloxane composite material prepared in Example 2 is used as a lithium battery electrode, and the cyclic voltammograms are for the first 5 cycles. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] The embodiments of the present invention are as follows:

[0041] Example 1:

[0042] like Figure 1 The flowchart is shown below:

[0043] Step 1) Preparation of siloxane: 1g CaSi2 was slowly added to 100mL of 11.8mol / L hydrochloric acid solution, reacted at 0℃ for 168h, then washed successively with acetone and deionized water until neutral, and freeze-dried at -30℃ to obtain the siloxane material. Figure 2 As shown in the electron microscope image, siloxane is a two-dimensional nanosheet structure with a relatively smooth surface and a distinct layered structure.

[0044] Step 2) Disperse 1 ml of pyrrole monomer in 100 ml of deionized water, and add 0.5 g of siloxane. Sonicate the mixture to disperse it evenly and obtain a mixed solution.

[0045] Step 3) Lower the temperature of the mixed solution to 0℃, and add 0.4mol / L ferric chloride aqueous solution dropwise at a rate of 0.1ml / min, and react for 2h;

[0046] Step 4) After the polymerization reaction is complete, wash with alcohol and distilled water respectively, and dry at 60°C to obtain polypyrrole-siloxane composite material, such as... Figure 3 As shown in the electron microscope image, the surface of the siloxane is densely coated with polypyrrole particles.

[0047] Polypyrrole-siloxane composite material was used to prepare supercapacitor electrodes: an electrode slurry was prepared by mixing polypyrrole-siloxane composite material, conductive carbon black, and sodium alginate binder in a ratio of 6:2:2. The slurry was coated on carbon paper and dried to obtain electrode sheets. The performance of the supercapacitor was tested using a three-electrode system with 1M (mol / L) sulfuric acid as the electrolyte. Figure 4The data are the conductivity test data of the conductive polymer-siloxane composite material in Examples 1-3. The siloxane nanosheets are almost insulators at room temperature, and the conductivity of the conductive polymer-siloxane composite material is greatly improved. Figure 5 The cyclic voltammogram of the polypyrrole-siloxane composite electrode is shown at a scan rate of 50 mV / s, with a pair of very obvious redox peaks. Figure 6 The constant current charge-discharge diagram of the polypyrrole-siloxane composite electrode at a current density of 0.01 A / g is shown.

[0048] Example 2:

[0049] Step 1) Preparation of siloxane: 1g CaSi2 was slowly added to 100mL of hydrochloric acid solution with a concentration of 11.8mol / L, and reacted at 0℃ for 168h. Then, it was washed with acetone and deionized water until neutral, and then freeze-dried at -30℃ to obtain siloxane material.

[0050] Step 2) Dissolve 1 ml of aniline and 25 μl of sulfonic acid in 50 ml of deionized water, then add 0.2 g of siloxane, and sonicate to disperse it evenly to obtain a mixed solution.

[0051] Step 3) Cool the mixed solution to 0°C and add 2.4M ammonium persulfate aqueous solution dropwise at a rate of 1 ml / min, and react for 12 h;

[0052] Step 4) After the polymerization reaction is complete, wash with alcohol and distilled water respectively, and dry at 60°C to obtain polyaniline-siloxane composite material. Figure 7 The electron microscope image of the polyaniline-siloxane composite material is shown, which shows that the polyaniline on the surface of the siloxane nanosheets has a loose and porous structure.

[0053] Polyaniline-siloxane composite material was used to prepare lithium battery anodes: an electrode slurry was prepared by mixing polyaniline-siloxane composite material, conductive carbon black, and sodium alginate binder in a ratio of 6:2:2. The slurry was coated on copper foil and dried to obtain an electrode sheet. A lithium sheet was used as the counter electrode, Ceglard2400 (PP) was used as the separator, LIR-2032 was used as the battery shell, and a 1M lithium hexafluorophosphate (LiPF6) electrolyte was prepared with a mixed solution of ethylene carbonate / diethyl carbonate (EC / DEC = 1:1, v / v) containing 5wt% vinyl fluorocarbonate (FEC) to test the electrode performance. Figure 8 The cyclic volt-ampere curves for the battery during its initial 5 cycles are shown.

[0054] Example 3:

[0055] Step 1) Preparation of siloxane: 1g CaSi2 is slowly added to 100mL of hydrochloric acid solution with a concentration of 11.8mol / L, reacted at 0℃ for 168h, and then washed with acetone and deionized water until neutral. The siloxane material is obtained by freeze drying at -30℃.

[0056] Step 2) Prepare 100 ml of 10% hydrochloric acid by mass. Take 50 ml of the solution into a beaker and weigh 0.1 M of 3,4-ethylenedioxythiophene and 10 g / L of styrene sulfonic acid into the beaker. Add 0.3 g of siloxane and mix thoroughly by ultrasonication to obtain a mixed solution.

[0057] Step 3) Weigh 0.05 mol / L ammonium persulfate and 0.1 mol / L ferric chloride and add them to 50 ml of 10% hydrochloric acid to obtain the oxidant. Then add the oxidant dropwise to the mixed solution at a rate of 1 ml / min.

[0058] Step 4) After the polymerization reaction is complete, wash with alcohol and distilled water respectively, and dry at 60°C to obtain poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid)-siloxane composite material.

Claims

1. A conductive polymer-siloxane composite material, characterized in that: The conductive polymer-siloxane composite material has a transverse dimension of 0.1-100 μm, a longitudinal dimension of less than 200 nm, and a conductivity greater than 0.1 S / cm. The conductive polymer-siloxane composite material includes siloxane nanosheets and a conductive polymer layer. The conductive polymer layer is coated on the surface of the siloxane nanosheets. The thickness of the conductive polymer layer is less than 100 nm. The conductive polymer layer is made of conductive polymer nanomaterials, which are one of nanoparticles, nanofibers, nanorods, nanosheets and nanofilms. The conductive polymer-siloxane composite material is prepared according to the following method: Step 1) Preparation of siloxane nanosheets: Under the temperature conditions of -30 to 5℃, 1g of calcium silicide CaSi2 is added to 100 to 1000mL of hydrochloric acid solution and reacted for 10 to 200h. After the reaction is completed, the product is washed with acetone and water until neutral, filtered and freeze-dried to obtain siloxane nanosheets. Step 2) Preparation of mixed solution: Dissolve the conductive polymer monomer in a solvent to obtain a conductive polymer monomer solution. Disperse the siloxane nanosheets obtained in Step 1) in the conductive polymer monomer solution and use ultrasonic mixing to mix the solution evenly to obtain a mixed solution. Step 3) Place the mixed solution on a magnetic stirring table, and add the oxidant dropwise to the mixed solution at a reaction temperature of 0-25°C and react for 1-24 hours to obtain the conductive polymer-siloxane composite material. Step 4) The conductive polymer-siloxane composite material obtained in step 3) is washed with alcohol and water in sequence, and then the washed conductive polymer-siloxane composite material is placed in an oven at 50-100℃ for drying to obtain the final conductive polymer-siloxane composite material. The conductive polymer monomer is one or more of pyrrole, aniline, thiophene, 3,4-ethylenedioxythiophene-styrene sulfonic acid, and acetylene.

2. A method for preparing the conductive polymer-siloxane composite material according to claim 1, characterized in that, Includes the following steps: Step 1) Preparation of siloxane nanosheets: Under the temperature conditions of -30 to 5℃, 1g of calcium silicide CaSi2 is added to 100 to 1000mL of hydrochloric acid solution and reacted for 10 to 200h. After the reaction is completed, the product is washed with acetone and water until neutral, filtered and freeze-dried to obtain siloxane nanosheets. Step 2) Preparation of mixed solution: Dissolve the conductive polymer monomer in a solvent to obtain a conductive polymer monomer solution. Disperse the siloxane nanosheets obtained in Step 1) in the conductive polymer monomer solution and use ultrasonic mixing to mix the solution evenly to obtain a mixed solution. Step 3) Place the mixed solution on a magnetic stirring table, and add the oxidant dropwise to the mixed solution at a reaction temperature of 0-25°C and react for 1-24 hours to obtain the conductive polymer-siloxane composite material. Step 4) Clean the conductive polymer-siloxane composite material obtained in step 3) with alcohol and water in sequence, and then place the cleaned conductive polymer-siloxane composite material in an oven at 50-100℃ to dry it, so as to obtain the final conductive polymer-siloxane composite material.

3. The method for preparing a conductive polymer-siloxane composite material according to claim 2, characterized in that: In step 1), the concentration of the hydrochloric acid solution is 0.05–11.8 mol / L, and the freeze-drying temperature is -50–-30°C.

4. The method for preparing a conductive polymer-siloxane composite material according to claim 2, characterized in that: In step 2), the mass ratio of the conductive polymer monomer to the siloxane nanosheet is 1:50 to 5:

1. The conductive polymer monomer is one or more of pyrrole, aniline, thiophene, 3,4-ethylenedioxythiophene-styrene sulfonic acid, and acetylene.

5. The method for preparing a conductive polymer-siloxane composite material according to claim 2, characterized in that: The mixed solution in step 2) also contains a dopant. The molar mass ratio of the conductive polymer monomer to the dopant is 100:1 to 2:

1. The dopant is one of protic acid, halogen, sulfonate, and sulfate.

6. The method for preparing a conductive polymer-siloxane composite material according to claim 2, characterized in that: In step 3), the molar mass ratio of the conductive polymer monomer to the oxidant is 1:1 to 1:3, and the oxidant is one or more of ferric chloride, potassium permanganate, sodium persulfate, ferric sulfate, ammonium persulfate, hydrogen peroxide, potassium dichromate, potassium iodate, and benzoyl peroxide.

7. The method for preparing a conductive polymer-siloxane composite material according to claim 2, characterized in that: The oxidant is added at a rate of 0.1–50 ml / min in step 3).

8. The method for preparing a conductive polymer-siloxane composite material according to claim 5, characterized in that: The protic acid is hydrochloric acid, nitric acid, sulfuric acid, perchloric acid, phosphoric acid, p-toluenesulfonic acid, benzenesulfonic acid, or acetic acid; the halogen is iodine or bromine; the sulfonate is one of sodium lignosulfonate, sodium p-aminobenzenesulfonate, sodium anthraquinone-2-sulfonate, sodium 2,7-naphthalenedisulfonate, sodium dodecylbenzenesulfonate, sodium p-methylbenzenesulfonate, sodium dodecylsulfonate, or sodium toluenesulfonate; the sulfate is one of zinc sulfate, cerium sulfate, nickel sulfate, magnesium sulfate, ammonium sulfate, sodium sulfate, stannous sulfate, sodium dodecyl sulfate, or potassium sulfate.

9. The application of the conductive polymer-siloxane composite material obtained by the preparation method according to any one of claims 2-8, characterized in that: The conductive polymer-siloxane composite material is used as an electrode material for energy storage devices, including lithium batteries, supercapacitors, and zinc batteries.

Images