CN115240991B - A method for manufacturing an ionic supercapacitor based on electroactive ionic liquid - Google Patents

Abstract

The invention discloses a construction method of a new ionic supercapacitor based on electroactive ionic liquid. First, the polymeric ionic liquid of alkyl imidazole chloride or bromide salt is reacted with the graphene oxide material, and after reduction, the polymeric ionic liquid-reduced graphene oxide composite PILs-rGO is obtained. Utilizing the ion exchange properties of ionic liquids, inorganic/organic anions with electrochemical redox activity are exchanged into the structural units of ionic liquids, and then the electroactive graphene material EAI‑PILs‑rGO is constructed. Furthermore, the electroactive graphene material with a relatively positive redox potential is used as the positive electrode and the more negative one is used as the negative electrode to construct a new asymmetric ionic supercapacitor, which can achieve rapid charging and discharging while effectively increasing the energy density of the graphene-based capacitor. , and has excellent structural stability. The method of the invention is simple, easy to operate, has universal applicability, and has excellent application prospects.

Description

A method of manufacturing an ionic supercapacitor based on electroactive ionic liquid

Technical field

The invention relates to the technical fields of electrode materials and energy storage, and in particular to a manufacturing method and application of a new ionic supercapacitor based on electroactive ionic liquid.

Background technique

With the rapid development of the global economy, the world's consumption of fossil fuels has increased significantly, which has accelerated the depletion of existing fossil fuel reserves. Therefore, the need to develop and expand sustainable clean energy and related technologies is considered a top priority around the world. . Supercapacitors have attracted widespread attention from many researchers in recent years due to their advantages such as high safety performance, long cycle life, and large storage capacity.

According to different energy storage mechanisms, supercapacitors can be divided into electric double layer capacitors and Faraday quasi-capacitors. Among them, electric double layer capacitors mainly store energy by adsorbing charges on the electrode surface. Faraday supercapacitors mainly achieve energy storage and conversion by generating Faraday capacitance through reversible oxidation-reduction reactions on and near the surface of active electrode materials. Therefore, the electrode materials in Faraday supercapacitors are the key to achieving energy storage and conversion, and are usually composed of metal oxides and carbon-based materials. Compared with electric double layer capacitors, Faraday supercapacitors tend to have higher specific capacitance and energy density, but metal oxides usually undergo phase changes during the dissolution or deposition process, which is likely to bring about changes in the electrode structure. Structural stability issues such as damage and dendrite formation affect the cycle stability of the battery to a certain extent. Therefore, in order to meet the growing energy demand of electronic devices and promote the development of new energy storage technologies, it is particularly important to find new electrode materials with low cost, high power and energy density, and good cycle stability.

Graphene is a commonly used electrode material component in capacitors. However, due to the existence of van der Waals forces, graphene obtained by chemical reduction is easily agglomerated, resulting in a reduction in its effective specific surface area, specific capacitance, conductivity and structural stability. has decreased, so inhibiting the agglomeration of graphene is the key to improving the application performance of graphene. Since the imidazole-based polymeric ionic liquid has a π-conjugated structure and is a cationic ionic liquid polymer, it can be combined with graphene oxide through π-π interaction or electrostatic adsorption, thereby effectively suppressing the agglomeration and accumulation of graphene materials. In addition, ionic liquids have strong structural designability and ion exchangeability, which can further give graphene materials special functionality.

By exchanging anions with electrochemical redox activity into the structural units of ionic liquids, a series of electroactive ionic liquids and their polymers with different redox potentials can be prepared. Combining electroactive ionic liquid polymers with graphene materials with high active surface area can effectively improve the structural stability of graphene materials and at the same time endow graphene materials with specific electrochemical reaction active centers. Furthermore, by selecting an electroactive graphene electrode material with a positive redox potential as the positive electrode and a negative one as the negative electrode, a series of electrodes with different voltage windows, stable electrode structures, and high power density and high energy density can be assembled. new ionic supercapacitors.

Contents of the invention

Based on the problems of low energy density of traditional capacitors, poor structural stability of metal oxide-based pseudocapacitor electrode materials, and low power density of traditional secondary batteries, the present invention introduces electrochemically active anions into the surface of graphene materials with high specific surface area to prepare a series of electrical Active graphene electrode material and its application in new ionic supercapacitors. During the charging and discharging process, only changes in the valence state of ions occur inside the electrode, and no phase change or dissolution deposition process of active components is involved, giving it excellent structural stability and the high power density of traditional capacitors and secondary batteries. high energy density.

In order to achieve the above object, the technical solution adopted by the present invention is: a manufacturing method of a new ionic supercapacitor based on electroactive ionic liquid, which includes the following steps:

1) Disperse graphene oxide (GO) in deionized water, and use the graded centrifugation method to obtain low-lamellar two-dimensional graphene oxide (GO) nanosheets;

2) Dissolve the alkyl imidazole bromide or alkyl imidazole chloride ionic liquid monomer and initiator in chloroform, heat and reflux at 70°C for 5 to 7 hours under the protection of _N2 , cool, wash, and vacuum dry to obtain the polymerized ionic liquid. (PILs);

3) Take an appropriate amount of the two-dimensional graphene oxide (GO) nanosheets obtained in step 1) and disperse them in deionized water, then add the PILs and hydrazine hydrate obtained in step 2) in sequence, and react at 90 to 100°C for 1 to 2 hours. The obtained product is filtered, centrifuged and washed to obtain polymerized ionic liquid-reduced graphene oxide composite (PILs-rGO);

4) Mix the PILs-rGO obtained in step 3) with inorganic salts or organic salt solutions of electroactive anions (EAI) with different electrochemical redox activities, and stir at room temperature for 1 hour to make anions with different electrochemical redox activities Perform exchange reaction with bromine or chloride ions in ionic liquids to obtain electroactive anion-polymerized ionic liquid-reduced graphene oxide composites (EAI-PILs-rGO) with different redox properties;

5) Disperse the EAI-PILs-rGO with different redox properties obtained in step 4) in deionized water, immerse the current collector or drop-coat the obtained EAI-PILs-rGO dispersion into the current collector, and then heat it at 60-80°C Dry for 12 to 24 hours, repeat the immersion or drip coating and drying steps 2 to 3 times to prepare active electrode materials with different redox potentials. Select the electrode material with a more positive redox potential as the positive electrode, and select the one with a more negative redox potential. The electrode material serves as the negative electrode and is assembled into a new asymmetric ionic supercapacitor based on electroactive ionic liquid.

Further, in the above-mentioned manufacturing method, step 1), the method of using graded centrifugation is used to obtain low-layer two-dimensional graphene oxide GO nanosheets, specifically: GO water is processed at a rotation speed of 1000r/min ~ 12000r/min. The dispersion is centrifuged stepwise from low speed to high speed. The supernatant obtained by centrifugation at low speed is continued to be centrifuged at high speed until there is no precipitate after centrifugation. The precipitate obtained by centrifugation at the highest speed is the second layer of low lamellae. 3D graphene oxide GO nanosheets.

Further, in the above-mentioned manufacturing method, step 2), the alkyl imidazole bromide salt or alkyl imidazole chloride salt ionic liquid monomer is an alkyl imidazole bromide salt or alkyl imidazole chloride salt ionic liquid monomer containing an unsaturated bond. body.

Further, in the above-mentioned manufacturing method, step 2), the initiator is azobisisobutyronitrile (AIBN).

Further, in the above-mentioned manufacturing method, according to the mass ratio, ionic liquid monomer: initiator = 50:1.

Further, in the above-mentioned manufacturing method, step 3), according to the mass ratio, two-dimensional graphene oxide (GO) nanosheets: polymeric ionic liquids (PILs) = 1:10.

Further, in the above-mentioned manufacturing method, step 4), inorganic salts or organic salts of electroactive anions (EAI) with different electrochemical redox activities include: potassium ferricyanide, phosphotungstic acid, cerium ammonium nitrate, amino acids, Sodium anthraquinone-2-sulfonate, disodium 4,5-dihydroxy-1,3 benzene disulfonate and sodium ferrocene benzene sulfonate.

Further, in step 5) of the above-mentioned manufacturing method, the current collector includes nickel foam, carbon paper, graphite felt, graphite plate and conductive glass.

Further, in step 5) of the above-mentioned manufacturing method, the concentration of the EAI-PILs-rGO dispersion is 1 to 10 mg/mL.

The beneficial effects of the present invention are:

1. The invention proposes to utilize the ion exchangeability of ionic liquids and the high conductivity and high specific surface area of graphene materials to prepare a series of electroactive graphene-based composite electrode materials. This material has excellent electrochemical redox reaction reversibility. , large specific surface area and adjustable redox potential, a series of new ionic supercapacitor systems with different electrochemical windows can be manufactured. The method is simple and universal.

2. The new ionic supercapacitor based on electroactive ionic liquid manufactured by the method of the present invention. The energy storage element is mainly graphene nanosheets and electroactive anions. While having high power density and high energy density, no electrode will occur. The phase change of materials has better structural stability.

3. The new ionic supercapacitor based on electroactive ionic liquid provided by the present invention introduces electrochemically active anions into the surface of graphene material with high specific surface area, prepares a series of electroactive graphene electrode materials, and applies them to new types of ionic supercapacitors. Ionic supercapacitor. During the charging and discharging process, only changes in the valence state of ions occur inside the electrode, and no phase change or dissolution deposition process of active components is involved, giving it excellent structural stability and the high power density of traditional capacitors and secondary batteries. high energy density.

Description of the drawings

Figure 1 is a TEM image of GO (a) and PILs-rGO composite material (b) prepared in Example 1.

Figure 2 is a comparison diagram of the cyclic voltammogram curves of [Fe(CN) ₆ ] ^3- -PILs-rGO (a) and PWA-PILs-rGO (b) prepared in Example 1 and PILs-rGO in sulfuric acid electrolyte.

Figure 3 shows the charge and discharge curves of two asymmetric supercapacitors assembled with EAI-PILs-rGO prepared in Example 1 and a symmetric supercapacitor assembled with PILs-rGO.

Figure 4 is a comparison diagram of the cyclic voltammogram curves of BQDS-PILs-rGO (a) and AQS-PILs-rGO (b) prepared in Example 2 and PILs-rGO in potassium chloride electrolyte.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and examples.

Example 1

(1) A method for manufacturing a new ionic supercapacitor based on inorganic electroactive ionic liquid, including the following steps:

1. Synthesis of low-layer two-dimensional graphene oxide (GO) nanosheets

Preparation of graphene oxide (GO): Graphene oxide (GO) was prepared by Hummers method. Place a three-necked round-bottomed flask filled with 135mL concentrated sulfuric acid (98wt%) in an ice water bath, add 4g high-purity graphite powder and 3.2g NaNO ₃ , stir until a uniform dispersion is achieved, and then slowly add 18g KMnO ₄ powder, keeping The temperature inside the bottle is always below 5℃. Then adjust the temperature to 5°C and react for 30 minutes until the black suspension turns into a gray-brown viscous substance. After leaving it at room temperature for five days, dilute it with a large amount of hot water, and add 30wt% hydrogen peroxide dropwise to reduce the remaining high-valent manganese ions until the solution turns bright yellow. Centrifuge and wash while hot until neutral to obtain graphene oxide (GO).

Disperse the obtained GO with deionized water, first centrifuge at 1000r/min for 10min, take the upper brown dispersion and centrifuge at 3000r/min for 10min, then take the supernatant and perform high-speed centrifugation, sequentially in the range of 3000r/min-12000r/min. Gradient centrifugation is performed from low speed to high speed, that is, the supernatant obtained by centrifugation at low speed is continued to be centrifuged at high speed until there is no precipitation after centrifugation. The precipitate at the highest speed is taken as the final product, which is low flakes. layer of two-dimensional graphene oxide (GO) nanosheets, vacuum dried, and set aside.

2. Synthesis of polymeric ionic liquids (PILs)

Synthesis of 1-vinyl-3-ethylimidazole bromide ionic liquid monomer: Add 1-vinyl imidazole and bromoethane with a molar ratio of 1:1.7 into a round-bottomed flask in sequence, and reflux in an oil bath at 70°C. React for 10 hours, and stop heating when reflux is no longer obvious. The obtained reactant was recrystallized three times with acetonitrile-ethyl acetate, and dried under vacuum to obtain 1-vinyl-3-ethylimidazole bromide ionic liquid.

Synthesis of polymeric ionic liquid 1-vinyl-3-ethylimidazole bromide salt: Add 5g of 1-vinyl-3-ethylimidazole bromide ionic liquid monomer to 100 mL of chloroform, and add 0.1g of 1-vinyl-3-ethylimidazole bromide ionic liquid monomer to it. Nitrogen bisisobutyronitrile (AIBN) was heated and refluxed in a 70°C oil bath for 6 hours under nitrogen protection. The resulting product was washed three times with chloroform and dried under vacuum to obtain the polymeric ionic liquid of 1-vinyl-3-ethylimidazole bromide ( PILs).

3. Synthesis of polymeric ionic liquid-reduced graphene oxide composite (PILs-rGO)

Disperse 50 mg of low-lamellar two-dimensional graphene oxide (GO) nanosheets in 50 mL of deionized water, add 500 mg of 1-vinyl-3-ethylimidazole bromide polymeric ionic liquid, and pipette under magnetic stirring. Add 35 μL of hydrazine hydrate reducing agent into the reaction vessel and react in a 90°C oil bath for 1 hour. The obtained product was filtered and washed by centrifugation with deionized water to remove excess reducing agent. After vacuum drying, the PILs-rGO composite is obtained.

4. Synthesis of inorganic electrochemical redox active anion-polymeric ionic liquid-reduced graphene oxide composite (EAI-PILs-rGO)

4.1) Synthesis of ferricyanide-polymeric ionic liquid-reduced graphene oxide composite ([Fe(CN) ₆ ] ^3- -PILs-rGO)

Take 10 mL of the 2 mg/mL aqueous dispersion of the PILs-rGO complex prepared in step 3, mix it with 5 mL of potassium ferricyanide solution with a concentration of 5 mmol/L, stir at room temperature for 1 h, and centrifuge the product with distilled water for 5 seconds. times, and vacuum dried to obtain [Fe(CN) ₆ ] ^3- -PILs-rGO composite, which is ready for use.

4.2) Synthesis of phosphotungstate-polymerized ionic liquid-reduced graphene oxide composite (PWA-PILs-rGO)

Take 10 mL of the 2 mg/mL aqueous dispersion of the PILs-rGO complex prepared in step 3, mix it with 5 mL of phosphotungstic acid solution with a concentration of 5 mmol/L, stir at room temperature for 1 h, and centrifuge the product with distilled water for 5 times. , vacuum drying to obtain the PWA-PILs-rGO composite for later use.

5. Assembling new ionic supercapacitors based on electroactive ionic liquids

[Fe(CN) ₆ ] ^3- -PILs-rGO composite and PWA-PILs-rGO composite were dispersed with 0.05wt% nafion aqueous solution respectively, and then drop-coated on the surface of 1cm×1cm carbon paper, vacuum 60℃ Dry to constant weight and repeat the above steps three times to obtain the electrode material. The carbon paper electrode loaded with [Fe(CN) ₆ ] ^3- -PILs-rGO was used as the positive electrode, the carbon paper electrode loaded with PWA-PILs-rGO was used as the negative electrode, the electrolyte was 2.5MH ₂ SO ₄ aqueous solution, and the GF40 glass fiber membrane was separator to assemble a sandwich-type asymmetric ionic supercapacitor.

(2) Testing

1. Figure 1 shows the TEM images of the prepared GO (a) and PILs-rGO composite (b).

Figure 1 (a) is the transmission electron microscope image of the obtained GO. As shown in Figure 1, the obtained graphene oxide has a two-dimensional lamellar structure and has abundant wrinkles on the surface.

(b) in Figure 1 is the transmission electron microscope image of the obtained PILs-rGO. As shown in Figure 1, the PILs-rGO composite material has a similar structure and morphology to graphene oxide, indicating that the introduction of PILs inhibits the agglomeration and stacking of GO during the reduction process, and the composite material still maintains a two-dimensional lamellar structure. .

2. Testing of electrochemical properties of inorganic electroactive anions-polymeric ionic liquid-graphene composite materials

The method is as follows: PILs-rGO, [Fe(CN) ₆ ] ^3- -PILs-rGO and PWA-PILs-rGO are respectively dispersed in 0.05wt% nafion aqueous solution. Take 7 μL of PILs-rGO (2mg·mL ^-1 ), [Fe(CN) ₆ ] ^3- -PILs-rGO (5mg·mL ^-1 ) and PWA-PILs-rGO (5mg·mL ^-1 ) water dispersions respectively. Drop coating onto the surface of a polished glassy carbon electrode with a diameter of 4 mm. After drying at room temperature, a thin film can be formed on the electrode surface to obtain PILs-rGO, [Fe(CN) ₆ ] ^3- -PILs-rGO and PWA-PILs. -rGO modified electrode.

Cyclic voltammetry test conditions: Use the modified electrode prepared above as the working electrode, use the silver/silver chloride electrode (Ag/AgCl) as the reference electrode, and use the platinum sheet as the counter electrode to form a three-electrode system, 2.5MH ₂ SO _4. The aqueous solution is the supporting electrolyte solution. The voltage windows are respectively set to: 0.2V~0.8V, -0.6V~0.1V, the scanning speed is 50mV/s, and the cyclic scanning is 100 times.

Figure 2 is a comparison chart of the cyclic voltammogram curves of the prepared PILs-rGO, [Fe(CN) ₆ ] ^3- -PILs-rGO (a) and PWA-PILs-rGO (b) in sulfuric acid electrolyte. As shown in Figure 2, the blank PILs-rGO modified electrode does not have obvious redox peaks under the positive and negative potential windows, but corresponds to [Fe(CN) ₆ ] ^3- -PILs-rGO(a) and PWA-PILs The CV curve of -rGO(b) electrode shows the characteristic redox peaks of [Fe(CN) ₆ ] ^3- and phosphotungstate respectively, and the reversibility is good; [Fe(CN) ₆ ] ^3- -PILs- The peak value of rGO is about 0.55V (vs.Ag/AgCl), while the most negative peak value of PWA-PILs-rGO is about -0.55V (vs.Ag/AgCl), indicating the subsequent assembly of asymmetric ionic supercapacitors When , the positive electrode material is [Fe(CN) ₆ ] ^3- -PILs-rGO, and the negative electrode material is PWA-PILs-rGO. The asymmetric capacitor assembled by the two can obtain a voltage window of about 1.1V. In addition, after 100 consecutive scans, the peak currents of the two attenuated less, indicating that the electrodes have good stability.

3. Testing of electrochemical properties of capacitors

The sandwich-type asymmetric ion supercapacitor assembled in step 5 was charged and discharged in a voltage window of -0.1V to 1.2V, with a current of 2mA.

Figure 3 shows the charge and discharge curves of two asymmetric supercapacitors assembled with EAI-PILs-rGO prepared in Example 1 and a symmetric supercapacitor assembled with PILs-rGO. As shown in Figure 3, the asymmetric supercapacitor loaded with electroactive anions can achieve stable charge and discharge, with a charge and discharge efficiency of approximately 93.44%. In addition, its discharge capacity is nearly 21% higher than that of the symmetric capacitor, indicating that the electroactive graphite The ene material can provide additional Faradaic capacitance, thereby effectively increasing the storage capacity of the capacitor.

Example 2

(1) A method for manufacturing a new ionic supercapacitor based on organic electroactive ionic liquid, including the following steps:

1. Synthesis of low-layer two-dimensional graphene oxide (GO) nanosheets

Same as Example 1.

2. Synthesis of polymeric ionic liquids (PILs)

Same as Example 1.

3. Synthesis of polymeric ionic liquid-reduced graphene oxide composite (PILs-rGO)

Same as Example 1.

4. Synthesis of organic electrochemical redox active anion-polymeric ionic liquid-reduced graphene oxide composite (EAI-PILs-rGO)

4.1) Synthesis of anthraquinone-2-sulfonate-polymeric ionic liquid-reduced graphene oxide composite (AQS-PILs-rGO)

Take 10 mL of an aqueous dispersion of 2 mg·mL ^-1 prepared from the PILs-rGO complex prepared in step 3, mix it with 2 mL of anthraquinone-2 sodium sulfonate solution with a concentration of 1 mmol/L, and stir at room temperature for 1 h. Centrifuge and wash with distilled water 5 times, and dry under vacuum to obtain the AQS-PILs-rGO complex for later use.

4.2) Synthesis of 4,5-dihydroxy-1,3 benzene disulfonate-polymerized ionic liquid-reduced graphene oxide composite (BQDS-PILs-rGO)

Take 10 mL of 2 mg/mL aqueous dispersion prepared from the PILs-rGO complex prepared in step 3, and mix it with 2 mL of 4,5-dihydroxy-1,3 benzene disulfonic acid disodium salt solution with a concentration of 1 mmol/L. , stirred at room temperature for 1 h, centrifuged and washed the product with distilled water 5 times, and dried under vacuum to obtain the BQDS-PILs-rGO complex for later use.

5. Assembling new ionic supercapacitors based on electroactive ionic liquids

After dispersing the AQS-PILs-rGO composite and BQDS-PILs-rGO composite with 0.05wt% nafion aqueous solution, they were drop-coated on the surface of 1cm × 1cm carbon paper, dried under vacuum at 60°C to constant weight, and then repeated the above After three steps, the electrode material can be obtained. The carbon paper electrode loaded with BQDS-PILs-rGO was used as the positive electrode, the carbon paper electrode loaded with AQS-PILs-rGO was used as the negative electrode, the electrolyte was 2.5MH ₂ SO ₄ aqueous solution, and the GF40 glass fiber membrane was used as the separator to assemble a sandwich-type asymmetric structure. Ionic supercapacitor.

(2) Testing

1. Testing of electrochemical properties of organic electroactive anions-polymeric ionic liquid-graphene composite materials

The method is as follows: PILs-rGO, AQS-PILs-rGO and BQDS-PILs-rGO are respectively dispersed in 0.05wt% nafion dewatering solution. Take 7 μL of PILs-rGO (2mg·mL ^-1 ), AQS-PILs-rGO (5mg·mL ^-1 ) and BQDS-PILs-rGO (5mg·mL ^-1 ) water dispersions and drop-coat them to a polished diameter of 4mm. After drying at room temperature, a thin film can be formed on the surface of the glassy carbon electrode to obtain PILs-rGO, AQS-PILs-rGO and BQDS-PILs-rGO modified electrodes.

Cyclic voltammetry test conditions: Use the modified electrode prepared above as the working electrode, use the silver/silver chloride electrode (Ag/AgCl) as the reference electrode, use the platinum sheet as the counter electrode to form a three-electrode system, and use 0.5M KCl aqueous solution In order to support the electrolyte solution, the voltage windows were set to: 0.45V~0.85V, -0.9V~-0.2V, the scanning speed was 50mV/s, and the scanning was 100 times.

Figure 4 is a comparison diagram of the cyclic voltammogram curves of BQDS-PILs-rGO (a) and AQS-PILs-rGO (b) prepared in Example 2 and PILs-rGO in potassium chloride electrolyte. As shown in Figure 4, the blank PILs-rGO modified electrode does not have obvious redox peaks under the positive and negative potential windows, while the CV corresponding to the BQDS-PILs-rGO (a) and AQS-PILs-rGO (b) electrodes The curves show the characteristic redox peaks of BQDS and AQS respectively, and the reversibility is good; the peak value of BQDS-PILs-rGO is about 0.6V (vs.Ag/AgCl), while the most negative peak of AQS-PILs-rGO The potential value is about -0.6V (vs.Ag/AgCl), indicating that when assembling asymmetric ion supercapacitors, the positive electrode material is BQDS-PILs-rGO, and the negative electrode material is AQS-PILs-rGO. The assembly of the two is different. Symmetrical capacitors give you a voltage window of about 1.2V. In addition, after 100 consecutive scans, the peak currents of the two attenuated less, indicating that the electrodes have good stability.

Claims (9)

1. A method for manufacturing an ionic supercapacitor based on electroactive ionic liquid, characterized in that it includes the following steps: 1) Disperse graphene oxide GO in deionized water, and use the graded centrifugation method to obtain low-lamellar two-dimensional graphene oxide GO nanosheets; 2) Dissolve the alkyl imidazole bromide or alkyl imidazole chloride ionic liquid monomer and initiator in chloroform, heat and reflux at 70°C for 5 to 7 hours under _N2 protection, cool, wash, and vacuum dry to obtain polymer ions Liquid PILs; 3) Take an appropriate amount of the two-dimensional graphene oxide GO nanosheets obtained in step 1) and disperse it in deionized water, then add the PILs and hydrazine hydrate obtained in step 2) in sequence, and react at 90~100°C for 1~2 h. The product is filtered, centrifuged and washed to obtain the polymerized ionic liquid-reduced graphene oxide composite PILs-rGO; 4) Mix the PILs-rGO obtained in step 3) with the inorganic salt or organic salt solution of the electroactive anion EAI with different electrochemical redox activities, and stir at room temperature for 1 h to obtain electroactive anions with different redox properties. -Polymeric ionic liquid-reduced graphene oxide composite EAI-PILs-rGO; 5) Disperse the EAI-PILs-rGO with different redox properties obtained in step 4) in deionized water, immerse the current collector or drop-coat the obtained EAI-PILs-rGO dispersion onto the current collector, and then heat it at 60~80 ℃ Dry for 12 to 24 hours, repeat the immersion or drip coating and drying steps 2 to 3 times to prepare active electrode materials with different redox potentials. Select the electrode material with a more positive redox potential as the positive electrode, and select the electrode material with a more negative redox potential. The electrode material serves as the negative electrode and is assembled into an asymmetric ionic supercapacitor based on electroactive ionic liquid. 2. The manufacturing method according to claim 1, characterized in that in step 1), the method of using graded centrifugation is used to obtain low-layer two-dimensional graphene oxide GO nanosheets, specifically: at 1000 r/min. Centrifuge the GO aqueous dispersion in a stepwise manner from low to high speed at ~12000 r/min. Use the supernatant obtained by centrifugation at low speed and continue centrifugation at high speed until there is no precipitation after centrifugation. Centrifuge at the highest speed. The obtained precipitate is low-lamellar two-dimensional graphene oxide GO nanosheets. 3. The manufacturing method according to claim 1, characterized in that in step 2), the alkyl imidazole bromide salt or alkyl imidazole chloride ionic liquid monomer is an alkyl imidazole bromide salt containing an unsaturated bond or Alkyl imidazole chloride ionic liquid monomer. 4. The manufacturing method according to claim 1, characterized in that in step 2), the initiator is azobisisobutyronitrile. 5. The manufacturing method according to claim 4, characterized in that, according to the mass ratio, ionic liquid monomer:initiator=50:1. 6. The manufacturing method according to claim 1, characterized in that, in step 3), according to the mass ratio, two-dimensional graphene oxide GO nanosheets:polymerized ionic liquid PILs=1:10. 7. The manufacturing method according to claim 1, characterized in that in step 4), the inorganic salts or organic salts of the electroactive anion EAI with different electrochemical redox activities include: potassium ferricyanide, ammonium cerium nitrate, Sodium anthraquinone-2-sulfonate, disodium 4,5-dihydroxy-1,3 benzene disulfonate and sodium ferrocene benzene sulfonate. 8. The manufacturing method according to claim 1, characterized in that in step 5), the current collector includes nickel foam, carbon paper, graphite felt, graphite plate and conductive glass. 9. The manufacturing method according to claim 1, characterized in that in step 5), the concentration of the EAI-PILs-rGO dispersion is 1~10 mg/mL.