CN107026027B - A kind of preparation method of the electrode material of supercapacitor - Google Patents

Abstract

The present invention provides a kind of preparation methods of the electrode material of supercapacitor, Fanglun 1414 is stirred together in dimethyl sulfoxide with potassium hydroxide to the dimethyl sulfoxide dispersion liquid for being completely dissolved to obtain Kevlar nanofiber, add acetic acid manganese solution, it stirs evenly, obtain cotton-shaped dispersion solution, freeze drier freeze-drying is put into after being filtered by vacuum, material, which is finally put into high-temperature calcination in tube furnace, can be obtained electrode material for super capacitor.The electrochemical performance of the electrode material obtained by means of the present invention, possess higher specific capacitance, and the performance of fast charge slow play is presented during constant current charge-discharge under larger current density, great business promotion value possesses preferable development prospect in following energy storage field.

Description

A kind of preparation method of the electrode material of supercapacitor

technical field

The invention belongs to the field of electricity and relates to an electrode material, in particular to a preparation method of an electrode material for a supercapacitor.

Background technique

Supercapacitors (EDLC), also known as electric double layer capacitors, as a new type of maintenance-free energy storage device between traditional capacitors and batteries, have become a hot spot of attention and research. Its specific power is more than 10 times that of batteries, its ability to store charges is higher than that of ordinary capacitors, and it has many advantages such as wide operating temperature range, fast charging and discharging, long cycle life, no pollution and zero emissions, etc. Electrode materials play a very important role in improving the performance of supercapacitors, and can be said to be the core part of supercapacitors. Therefore, the development of electrode materials with excellent performance is the most critical topic in supercapacitor research.

Contents of the invention

The object of the present invention is to provide a kind of preparation method of the electrode material of supercapacitor, the preparation method of the electrode material of described this supercapacitor will solve the supercapacitor specific capacity in the prior art is not high, electrochemical performance is not strong technical problem.

The invention provides a kind of preparation method of the electrode material of supercapacitor, comprises the following steps:

1) Cut the Kevlar fiber into short lines with a length of 0.1 to 20 cm;

2) Potassium hydroxide is weighed and ground into powder;

3) Pour the Kevlar fiber and potassium hydroxide into the dimethyl sulfoxide solvent and stir for 72 to 240 hours until the Kevlar fiber is completely dissolved to obtain a dimethyl sulfoxide dispersion of Kevlar nanofibers, Kevlar fibers , The material ratio of potassium hydroxide and dimethyl sulfoxide solvent is 0.1~2 grams: 1.0~3.0 grams: 500~2000 milliliters;

4) Mix the manganese acetate solution with a concentration of 1 to 5 mg/mL and the above-mentioned dimethyl sulfoxide dispersion of Kevlar nanofibers, and the manganese acetate solution and the dimethyl sulfoxide dispersion of Kevlar nanofibers The volume ratio of the liquid is 100~200ml: 100~200ml, stir for 1~5 hours until the dispersion is evenly mixed;

5) Vacuum filter the flocculent dispersion liquid mixed in step 4, and wash the potassium ions with deionized water, then take the solid;

6) Put the solid obtained in step 5) into a freeze dryer to dry for 72 to 120 hours, then calcinate and carbonize at a high temperature of 600 to 900 degrees Celsius under the protection of nitrogen, take out the carbonized solid and grind it into powder;

7) Mix the powder material obtained in step 6), acetylene black, and polyvinylidene fluoride in a mass ratio of 50-99:1-49:1-49, grind them evenly, and then use them as supercapacitor electrode materials.

Further, the mass ratio of the Kevlar fiber to potassium hydroxide is between 1:1 and 1:5.

Further, the prepared manganese acetate solution has a concentration of 2 mg/mL.

Further, the vacuum-filtered solid in step 5) needs to be freeze-dried for 24 hours to 72 hours.

Further, step 6) the high-temperature calcination must be under the protection of nitrogen, the temperature is 600-900 degrees, and the temperature is kept for more than 3 hours, and the heating rate is 2-10 degrees per minute.

Further, in step 7), polyvinylidene fluoride is dissolved in N-methylpyrrolidone before grinding.

In the present invention, poly-p-phenylene terephthalamide (Kevlar fiber) fibers are stirred together with potassium hydroxide (KOH) in dimethyl sulfoxide (DMSO) until they are completely dissolved to obtain Kevlar nanofibers. Methyl sulfoxide dispersion. Then add manganese acetate solution and stir evenly to obtain a flocculent dispersion solution. It was vacuum filtered and put into a freeze dryer to freeze dry. Finally, the material is put into a tube furnace for high-temperature calcination to obtain the supercapacitor electrode material. The electrode material obtained by the method of the present invention has excellent electrochemical properties, has a high specific capacitance, and exhibits the performance of fast charge and slow discharge in the constant current charge and discharge process at a large current density.

The invention utilizes the Kevlar fiber to prepare the electrode material of the nanoscale fiber network structure, which has good chemical stability, adds pseudocapacitance effect after being doped with manganese, and can greatly improve its electrochemical performance. The synthesis process of the electrode material of the present invention is simple and low in cost, and in the aqueous electrolyte, the mass specific capacity at a current density of 1 A/g is in the range of 510-820 F/g.

Compared with the prior art, the technical progress of the present invention is remarkable. The supercapacitor electrode material of the present invention has electric double-layer capacitance effect and pseudocapacitance effect, so the electrode material has relatively large electrochemical performance, provides specific capacity, and the synthesis method of the present invention is simple, and the prepared nano-scale fiber network structure, has a good electric double layer effect, has great commercial promotion value, and has a good development prospect in the future energy storage field.

Description of drawings

FIG. 1 is a scanning electron microscope picture of the electrode material of Example 1.

2 is a transmission electron microscope image of the electrode material of Example 1.

Fig. 3 is the constant current charge and discharge curves of the electrode material of Example 1 at different current densities.

Figure 4 is the cyclic voltammetry curves of the electrode material of Example 1 at different scan rates.

Fig. 5 is the XRD pattern of the electrode material obtained in Example 1 after different carbonization temperatures.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

A method for preparing supercapacitor electrode material ANFS/Mn ²⁺ .

Cut 1.0341g Kevlar fiber into about 1cm length, put it into 500mL DMSO, weigh 1.5023g KOH, grind it into powder and pour it into DMSO solution, stir it magnetically for 168 hours to get a brown-red liquid, and the Kevlar fiber is completely dissolved In DMSO solution, ANFS solution was obtained.

Prepare a manganese acetate solution with a concentration of 2mg/mL and pour it into 200mL of ANFS solution, and immediately stir it mechanically for 10h until the solution becomes a uniformly mixed flocculent gel solution.

Use 22nm filter paper to vacuum filter the flocculent gel solution, and use 0.5L~1L deionized water for suction filtration and washing.

The film-like solid obtained by suction filtration was collected, freeze-dried, and then placed in a tube furnace at a heating rate of 5°C/min to 700°C (600, 800°C) for 3 hours. The carbonized solid is taken out and ground into powder to obtain the supercapacitor electrode material.

Grind the prepared electrode material together according to the ratio of electrode material: acetylene black: PVDF=8:1:1 (mass ratio, PVDF dissolved in 1-methylpyrrolidone in advance), and spread it on the titanium mesh after half an hour , tested in 4M KOH electrolyte after drying.

Example 2

A method for preparing supercapacitor electrode material ANFS/Mn ²⁺ .

Cut 1.005g Kevlar fiber into about 1cm length, put it into 500mL DMSO, weigh 1.5072g KOH, grind it into powder and pour it into DMSO solution, stir it magnetically for 168 hours to get a brown-red liquid, and the Kevlar fiber is completely dissolved In DMSO solution, ANFS solution was obtained.

Prepare a manganese acetate solution with a concentration of 2mg/mL and pour it into 200mL of ANFS solution, and immediately stir it mechanically for 10h until the solution becomes a uniformly mixed flocculent gel solution.

Use 22nm filter paper to vacuum filter the flocculent gel solution, and use 0.5L~1L deionized water for suction filtration and washing.

The film-like solid obtained by suction filtration was collected, freeze-dried, and then placed in a tube furnace at a heating rate of 5°C/min to 800°C for 3 hours. The carbonized solid is taken out and ground into powder to obtain the supercapacitor electrode material.

Grind the prepared electrode material together according to the ratio of electrode material: acetylene black: PVDF=8:1:1 (mass ratio, PVDF dissolved in 1-methylpyrrolidone in advance), and spread it on the titanium mesh after half an hour , tested in 4M KOH electrolyte after drying.

Example 3

A method for preparing supercapacitor electrode material ANFS/Mn ²⁺ .

Cut 2.0137g Kevlar fiber into about 1cm length, put it into 500mL DMSO, weigh 1.5001g KOH, grind it into powder and pour it into DMSO solution, stir it magnetically for 200 hours to get a brown-red liquid, and the Kevlar fiber is completely dissolved In DMSO solution, ANFS solution was obtained.

Pour manganese acetate solution with a concentration of 4 mg/mL into 200 mL of ANFS solution, and immediately stir mechanically for 10 h until the solution becomes a uniformly mixed flocculent gel solution.

Use 22nm filter paper to vacuum filter the flocculent gel solution, and use 0.5L~1L deionized water for suction filtration and washing.

The film-like solid obtained by suction filtration was collected, freeze-dried, and then placed in a tube furnace at a heating rate of 5°C/min to 900°C for 3 hours. Take out the carbonized solid and grind it into powder to get the supercapacitor electrode material

The electrode material finally obtained in the above three examples is used as the supercapacitor active material, and is ground together according to the ratio of active material: acetylene black: PVDF= 8:1:1 (mass ratio, PVDF is dissolved in 1-methylpyrrolidone in advance), After half an hour, it was coated on nickel foam and tested in 4M KOH electrolyte after drying. Its constant current charge and discharge curves at different current densities are shown in Figure 3, using the calculation formula and The formula can calculate the specific capacity of the composite material to be 510~820F/g.

Although specific embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, substitutions, Modifications and variations, the scope of the invention is defined by the appended claims and their equivalents.

Claims (3)

1. a kind of preparation method of the electrode material of supercapacitor, it is characterised in that the following steps are included:

1) Kafra fiber is cut into the short-term of 0.1~20 centimeter length；

2) potassium hydroxide is weighed, is pulverized；

3) Kafra fiber and potassium hydroxide are poured into dimethylsulfoxide solvent stir 72~240 hours it is complete to Kafra fiber Dissolution, obtains the dimethyl sulfoxide dispersion liquid of Kevlar nanofiber, the object of Kafra fiber, potassium hydroxide and dimethylsulfoxide solvent Material is than being 0.1~2 gram: 1.0~3.0 gram: 500~2000 milliliters；

4) the dimethyl sulfoxide dispersion liquid of acetic acid manganese solution and above-mentioned Kevlar nanofiber that concentration is 1~5mg/mL is mixed It closes, the volume ratio of the dimethyl sulfoxide dispersion liquid of the acetic acid manganese solution and Kevlar nanofiber is 100~200 milliliters: 100 ~200 milliliters, stirring 1~5 hour uniformly mixed to dispersion liquid；

5) the cotton-shaped dispersing liquid for mixing step 4), vacuum filtration, and will be after its potassium ion wash clean with deionized water Take out solid；

6) after the solid for obtaining step 5) is put into freeze drier drying 72~120 hours, under nitrogen protection, 600~900 Degree Celsius lower high-temperature calcination is carbonized and keeps the temperature 3 hours or more, and heating rate is taken out carbonized solid and be ground at 2~10 degrees/min Powder；

It 7) is in mass ratio that 50-99:1-49:1-49 is mixed by dusty material that step 6) obtains, acetylene black, Kynoar, Kynoar is dissolved in N-Methyl pyrrolidone before the milling, can be used as electrode of super capacitor material after grinding uniformly Material.

2. a kind of preparation method of the electrode material of supercapacitor according to claim 1, it is characterised in that: Kevlar The mass ratio of fiber and potassium hydroxide is between 1:1~1:5.

3. a kind of preparation method of the electrode material of supercapacitor according to claim 1, it is characterised in that: matched The concentration of acetic acid manganese solution is in 2mg/mL.