A compound based on 3,4-ethylenedioxythiophene, a preparation method and application thereof, and an electrode material and a preparation method thereof

Abstract

The present invention belongs to the field of electrode material technology, and provides a compound based on 3,4-ethylenedioxythiophene, a preparation method and application thereof, and an electrode material and a preparation method thereof, which solves the problem of low energy density of supercapacitors in the prior art. The preparation method of the compound comprises the following steps: under a protective atmosphere, aminomethyl EDOT, 2,3-naphthalene dihydride and propionic acid are mixed, and reacted to obtain a compound based on 3,4-ethylenedioxythiophene. The present invention synthesizes a novel EDOT-2,3-naphthalene diimide structural monomer by p-doping EDOT with excellent electrochemical performance and n-doping 2,3-naphthalene diimide containing a carbonyl group in the basic unit of a bipolar conductive polymer, and applies it to a supercapacitor after electropolymerization, with a forward voltage of 1.6V and a negative voltage of 2V, thereby realizing a wide voltage window and achieving high energy density.

Description

Technical Field

[0001] The present invention relates to the technical field of electrode materials, and in particular to a 3,4-ethylenedioxythiophene-based compound, a preparation method and application thereof, and an electrode material and a preparation method thereof. Background Art

[0002] With the rapid consumption of global energy, energy storage and reuse is an important means to achieve the dual carbon goals. Compared with lithium batteries, supercapacitors have higher power density and can achieve rapid charging and discharging in a short time. At the same time, supercapacitors can also avoid the problems of precious metal scarcity and environmental pollution. Therefore, they have been widely used in urban public transportation systems. However, the low energy density has also limited the rapid development of supercapacitors to a certain extent. Therefore, it is of great significance to provide an electrode material with high energy density. Summary of the invention

[0003] The purpose of the present invention is to overcome the problems existing in the prior art and to provide a 3,4-ethylenedioxythiophene-based compound and a preparation method and application thereof as well as an electrode material and a preparation method thereof.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a compound based on 3,4-ethylenedioxythiophene, the structure of the compound is:

[0006]

[0007] The present invention also provides a method for preparing the 3,4-ethylenedioxythiophene-based compound, comprising the following steps:

[0008] Under a protective atmosphere, aminomethyl EDOT, 2,3-naphthalene dianhydride and propionic acid are mixed and reacted to obtain the 3,4-ethylenedioxythiophene-based compound.

[0009] Preferably, the molar ratio of the aminomethyl EDOT to 2,3-naphthalene dianhydride is 2-3:1.

[0010] Preferably, the mass volume ratio of the aminomethyl EDOT and propionic acid is 1 g:8-10 mL.

[0011] Preferably, the reaction temperature is 125-130°C.

[0012] Preferably, the reaction time is 16 to 24 hours.

[0013] The present invention also provides application of the 3,4-ethylenedioxythiophene-based compound in electrode materials.

[0014] The present invention also provides an electrode material prepared from raw materials containing the following proportions:

[0015] A 3,4-ethylenedioxythiophene-based compound, tetrabutylammonium hexafluorophosphate, and a solvent;

[0016] The solvent comprises dichloromethane and acetonitrile, and the volume ratio of dichloromethane to acetonitrile is 1.5-2.5:2.5-3.5;

[0017] The mass volume ratio of the 3,4-ethylenedioxythiophene-based compound to the solvent is 1 g: 0.5 to 0.6 L;

[0018] The molar volume ratio of the tetrabutylammonium hexafluorophosphate to the solvent is 0.05-0.1 mol:1L.

[0019] The present invention also provides a method for preparing the electrode material, comprising the following steps:

[0020] A compound based on 3,4-ethylenedioxythiophene, tetrabutylammonium hexafluorophosphate and a solvent are mixed and electropolymerized to obtain the electrode material.

[0021] Preferably, the voltage of the electropolymerization is -0.3 to 1.6 V, the scanning speed is 100 to 120 mV / s, and the number of turns is 10 to 12 turns.

[0022] The beneficial effects of the present invention are:

[0023] The present invention adopts bipolar conductive polymer to prepare electrode material, and realizes both p-doping and n-doping by p-doping 3,4-ethylenedioxythiophene (EDOT) with excellent electrochemical performance and n-doping 2,3-naphthalene diimide containing carbonyl in the basic unit of bipolar conductive polymer, thereby synthesizing a novel EDOT-2,3-naphthalene diimide structure monomer, which is applied to supercapacitor electrode material after electropolymerization, and the forward voltage reaches 1.6V and the negative voltage reaches -2V, thereby realizing high energy density by realizing a wide voltage window; in addition, at 5A / cm 3 At a current density of 10.8 F / cm, the forward volumetric capacitance of the electrode material prepared by the present invention is 108 F / cm 3 , negative volume capacitance is 11.5F / cm 3 , with excellent conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a nuclear magnetic hydrogen spectrum characterization diagram of the compound based on 3,4-ethylenedioxythiophene in Example 1;

[0025] Figure 2The electrochemical polymerization curve of the electrode material in Example 1 (Potential—voltage, Current—current);

[0026] Figure 3 The cyclic voltammetry curves of the electrode material in Example 1 at different forward scan rates (Potential—voltage, Current—current);

[0027] Figure 4 The charge and discharge curves of the electrode material in Example 1 at different forward current densities (Time—time, Potential—voltage);

[0028] Figure 5 The cyclic voltammetry curves of the electrode material in Example 1 at different negative scan rates (Potential—voltage, Current—current);

[0029] Figure 6 The charge and discharge curves of the electrode material in Example 1 at different negative current densities (Time—time, Potential—voltage);

[0030] Figure 7 This is the impedance spectrum of the electrode material in Example 1. DETAILED DESCRIPTION

[0031] The present invention provides a compound based on 3,4-ethylenedioxythiophene, the structure of the compound is:

[0032]

[0033] The present invention also provides a method for preparing the 3,4-ethylenedioxythiophene-based compound, comprising the following steps:

[0034] Under a protective atmosphere, aminomethyl EDOT, 2,3-naphthalene dianhydride and propionic acid are mixed and reacted to obtain the 3,4-ethylenedioxythiophene-based compound.

[0035] In the present invention, the protective atmosphere is preferably nitrogen, helium or neon.

[0036] In the present invention, the molar ratio of the aminomethyl EDOT to 2,3-naphthalene dianhydride is preferably 2 to 3:1, more preferably 2.2 to 2.8:1, and even more preferably 2.4 to 2.6:1.

[0037] In the present invention, the mass volume ratio of the aminomethyl EDOT and propionic acid is preferably 1 g: 8 to 10 mL, more preferably 1 g: 8.5 to 9.5 mL, and even more preferably 1 g: 8.7 to 9.3 mL.

[0038] In the present invention, the chemical formula of the reaction is:

[0039]

[0040] In the present invention, the reaction temperature is preferably 125 to 130°C, more preferably 126 to 129°C, and even more preferably 127 to 128°C.

[0041] In the present invention, the reaction time is preferably 16 to 24 hours, more preferably 18 to 22 hours, and even more preferably 19 to 21 hours.

[0042] In the present invention, after the reaction is completed, the obtained system is post-treated to obtain the 3,4-ethylenedioxythiophene-based compound.

[0043] In the present invention, the post-processing comprises the following steps:

[0044] The system obtained by the reaction is naturally cooled, then poured into a beaker filled with water and allowed to stand, and after precipitation is precipitated, it is filtered to obtain a solid phase, and the solid phase is sequentially washed with water, dried and eluted for purification, and the obtained eluate is subjected to reduced pressure distillation to remove the solvent to obtain the 3,4-ethylenedioxythiophene-based compound.

[0045] In the present invention, the target temperature of the natural cooling is 20-25°C, more preferably 21-24°C, and more preferably 22-23°C; the volume ratio of water to propionic acid is preferably 120-150:8-10, more preferably 125-145:8.5-9.5, and more preferably 130-140:8.7-9.3; the number of water washings is preferably ≥2 times, more preferably ≥3 times, and more preferably ≥4 times; the stationary phase for elution and purification is silica gel, and the mesh number of the silica gel is preferably 300-400 mesh, more preferably 320-380 mesh, more preferably 330-370 mesh; the mobile phase for elution and purification preferably comprises dichloromethane and petroleum ether, and the volume ratio of dichloromethane to petroleum ether is preferably 4.5-5.5:0.5-1.5, more preferably 4.6-5.4:0.6-1.4, more preferably 4.7-5.3:0.7-1.3; the filtration, drying and reduced pressure distillation are not limited to specific conditions, and conventional technical means in the art can be used.

[0046] The present invention also provides application of the 3,4-ethylenedioxythiophene-based compound in electrode materials.

[0047] The present invention also provides an electrode material prepared from raw materials containing the following proportions:

[0048] A 3,4-ethylenedioxythiophene-based compound, tetrabutylammonium hexafluorophosphate, and a solvent;

[0049] The solvent comprises dichloromethane and acetonitrile, wherein the volume ratio of dichloromethane to acetonitrile is 1.5-2.5:2.5-3.5, preferably 1.6-2.4:2.6-3.4, more preferably 1.7-2.3:2.7-3.3, and more preferably 1.8-2.2:2.8-3.2;

[0050] The mass volume ratio of the 3,4-ethylenedioxythiophene-based compound to the solvent is 1 g: 0.5 to 0.6 L, preferably 1 g: 0.51 to 0.59 L, more preferably 1 g: 0.52 to 0.58 L, and more preferably 1 g: 0.53 to 0.57 L;

[0051] The molar volume ratio of the tetrabutylammonium hexafluorophosphate to the solvent is 0.05-0.1 mol:1L, preferably 0.06-0.09 mol:1L, more preferably 0.07-0.08 mol:1L, and more preferably 0.072-0.078 mol:1L.

[0052] The present invention also provides a method for preparing the electrode material, comprising the following steps:

[0053] A compound based on 3,4-ethylenedioxythiophene, tetrabutylammonium hexafluorophosphate and a solvent are mixed and electropolymerized to obtain the electrode material.

[0054] In the present invention, the voltage of the electropolymerization is preferably -0.3 to 1.6 V, more preferably 0.2 to 1.1 V, and more preferably 0.5 to 0.8 V; the scanning speed is preferably 100 to 120 mV / s, more preferably 105 to 115 mV / s, and more preferably 108 to 112 mV / s; the number of turns is preferably 10 to 12 turns, and more preferably 11 turns.

[0055] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0056] Example 1

[0057] In a nitrogen atmosphere, 10 mmol aminomethyl EDOT, 4 mmol 2,3-naphthalene dianhydride and 15 mL propionic acid were mixed and reacted at 127°C for 20 hours. After the reaction, the obtained system was naturally cooled to 22°C, then poured into a beaker filled with 130 mL of water and allowed to stand. After precipitation, the solid phase was filtered to obtain a solid phase, which was washed, dried and eluted for purification in sequence, wherein the number of water washings was 3 times, the stationary phase for elution purification was 350 mesh silica gel, and the mobile phase was dichloromethane and petroleum ether (the volume ratio of dichloromethane to petroleum ether was 5:1). The obtained eluate was distilled under reduced pressure to remove the solvent to obtain the 3,4-ethylenedioxythiophene-based compound.

[0058] The compound based on 3,4-ethylenedioxythiophene prepared in this example was characterized by hydrogen nuclear magnetic spectrum, and the hydrogen nuclear magnetic spectrum characterization diagram of the compound based on 3,4-ethylenedioxythiophene in this example was obtained, as shown in FIG. Figure 1 As shown. Figure 1 It can be seen that the hydrogen spectrum data of the compound based on 3,4-ethylenedioxythiophene prepared in this example is 1 HNMR(400MHz,Chloroform-d)δ8.47-8.32(m,2H),8.17-8.02(m,2H),7.86-7.65(m,2H),6.45 -6.26(m,2H),4.57(p,J=6.7Hz,1H),4.35-4.27(m,1H),4.22-4.03(m,2H),4.02-3.92(m,1H).

[0059] 2 g of the 3,4-ethylenedioxythiophene-based compound prepared in this example, 0.1 mol of tetrabutylammonium hexafluorophosphate, 400 mL of dichloromethane and 600 mL of acetonitrile were mixed and electropolymerized (the voltage was set to 1.0 V, the scanning speed was 110 mV / s, and the number of cycles was 11) to obtain an electrode material.

[0060] The electrode material prepared in this example was tested using a conventional three-electrode system, with ITO as the film-forming substrate, glass wire as the counter electrode, and Ag / Ag as the + As a reference electrode, the electrochemical polymerization curve of the electrode material in this embodiment is obtained, such as Figure 2 shown; from Figure 2 It can be seen that with the increase or decrease of the number of polymerization cycles, the current density gradually increases, indicating that polymers are continuously formed on the substrate, proving the successful occurrence of the polymerization reaction; lithium perchlorate (0.1 mol / L) is used as the supporting electrolyte, acetonitrile is used as the solvent, and the prepared electrode material is electrochemically characterized by the same three-electrode system, and the cyclic voltammetry curves of the electrode material in this embodiment at different forward scan rates are obtained, as shown in FIG. Figure 3shown; from Figure 3 It can be seen that the forward redox potential of the electrode material is between 0.2V and 0V, and even at a high scan rate, it also presents a redox peak similar to that at a low scan rate, indicating that the p-doped electrode material has good reversibility and can reach a wide voltage operating range of 1.6V in the forward direction; the charge and discharge curves of the electrode material in this embodiment at different forward current densities are shown in FIG. Figure 4 shown; from Figure 4 It can be obtained at 5A / cm 3 At a current density of 108 F / cm 3 , and as the current density increases, the rate performance remains at a good level. At the same time, it can be seen that there is almost no voltage drop in the positive charge and discharge curve, indicating that the material has a good positive energy storage capacity; the cyclic voltammetry curve of the electrode material in this embodiment at different negative scan rates, such as Figure 5 shown; from Figure 5 It can be seen that the negative reduction-oxidation potential of the electrode material is around -1.7V and -1.0V, and the negative working voltage reaches -2V, showing the wide negative working voltage of the material; the charge and discharge curves of the electrode material at different negative current densities in this embodiment are as follows: Figure 6 shown; from Figure 6 It can be seen that at 5A / cm 3 At a current density of , the negative volumetric capacitance of the electrode material in this embodiment is 11.5 F / cm 3 , showing that the material has good negative energy storage capacity. The prepared electrode material is subjected to impedance testing to obtain an impedance spectrum of the electrode material in this embodiment, as shown in FIG. Figure 7 shown; from Figure 7 It can be seen that the electrode material presents a straight line almost perpendicular to the horizontal axis in the low-frequency region, which represents a fast charge transfer capability. At the same time, the intersection of the semicircle presented in the high-frequency region and the horizontal axis is very small, indicating that the material has a small interface resistance, indicating that the electrode material prepared in this embodiment has excellent conductivity.

[0061] Example 2

[0062] In a helium atmosphere, 9 mmol aminomethyl EDOT, 3.5 mmol 2,3-naphthalene dianhydride and 14 mL propionic acid were mixed and reacted at 128°C for 18.5 h. After the reaction, the obtained system was naturally cooled to 25°C, then poured into a beaker containing 135 mL of water and allowed to stand. After precipitation, the solid phase was filtered to obtain a solid phase, which was washed, dried and eluted for purification in sequence. The number of water washings was 4 times, the stationary phase for elution purification was 300 mesh silica gel, and the mobile phase was dichloromethane and petroleum ether (the volume ratio of dichloromethane to petroleum ether was 4.7:1.1). The obtained eluate was distilled under reduced pressure to remove the solvent to obtain the 3,4-ethylenedioxythiophene-based compound.

[0063] Example 3

[0064] In a neon atmosphere, 12mmol aminomethyl EDOT, 5.2mmol 2,3-naphthalene dianhydride and 17.5mL propionic acid were mixed and reacted at 125°C for 21.5h. After the reaction, the obtained system was naturally cooled to 20°C, then poured into a beaker filled with 150mL water and allowed to stand. After precipitation, it was filtered to obtain a solid phase, and the solid phase was washed, dried and eluted for purification in sequence, wherein the number of water washings was 4 times, the stationary phase for elution purification was 400 mesh silica gel, and the mobile phase was dichloromethane and petroleum ether (the volume ratio of dichloromethane to petroleum ether was 5.2:0.7), and the obtained eluate was distilled under reduced pressure to remove the solvent to obtain the 3,4-ethylenedioxythiophene-based compound.

[0065] It can be seen from the above embodiments that the present invention provides a compound based on 3,4-ethylenedioxythiophene, which achieves both p- and n-doping by p-doping 3,4-ethylenedioxythiophene (EDOT) with excellent electrochemical performance in the basic unit of the bipolar conductive polymer and n-doping 2,3-naphthalene diimide containing a carbonyl group, thereby synthesizing a novel EDOT-2,3-naphthalene diimide structure monomer, which is applied to supercapacitor electrode materials after electropolymerization, and the forward voltage reaches 1.6V and the negative voltage reaches -2V, thereby achieving a high energy density by realizing a wide voltage window; in addition, at 5A / cm 3 At a current density of 10.8 F / cm, the forward volumetric capacitance of the electrode material prepared by the present invention is 108 F / cm 3 , negative volume capacitance is 11.5F / cm 3 , with excellent conductivity.

[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A compound based on 3,4-ethylenedioxythiophene, It is characterized in that The structure of the compound is:

2. The method for preparing the 3,4-ethylenedioxythiophene-based compound according to claim 1, It is characterized in that It includes the following steps: Under a protective atmosphere, aminomethyl EDOT, 2,3-naphthalene dianhydride and propionic acid are mixed and reacted to obtain the 3,4-ethylenedioxythiophene-based compound; The structural formula of the aminomethyl EDOT is 3. The preparation method according to claim 2, It is characterized in that The molar ratio of the aminomethyl EDOT to 2,3-naphthalene dianhydride is 2-3:

1.

4. The preparation method according to claim 2 or 3, It is characterized in that The mass volume ratio of the aminomethyl EDOT and propionic acid is 1 g:8-10 mL.

5. The preparation method according to claim 4, It is characterized in that The reaction temperature is 125-130°C.

6. The preparation method according to claim 5, It is characterized in that The reaction time is 16 to 24 hours.

7. Use of the 3,4-ethylenedioxythiophene-based compound according to claim 1 in electrode materials.

8. An electrode material, It is characterized in that Prepared from raw materials containing the following proportions: The 3,4-ethylenedioxythiophene-based compound according to claim 1, tetrabutylammonium hexafluorophosphate and a solvent; The solvent comprises dichloromethane and acetonitrile, and the volume ratio of dichloromethane to acetonitrile is 1.5-2.5:2.5-3.5; The mass volume ratio of the 3,4-ethylenedioxythiophene-based compound to the solvent is 1 g: 0.5 to 0.6 L; The molar volume ratio of the tetrabutylammonium hexafluorophosphate to the solvent is 0.05-0.1 mol:1L.

9. The method for preparing the electrode material according to claim 8, It is characterized in that It includes the following steps: The 3,4-ethylenedioxythiophene-based compound according to claim 1, tetrabutylammonium hexafluorophosphate and a solvent are mixed and electropolymerized to obtain the electrode material.

10. The preparation method according to claim 9, It is characterized in that The voltage of the electropolymerization is -0.3 to 1.6 V, the scanning speed is 100 to 120 mV / s, and the number of turns is 10 to 12 turns.

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