CN114093684B - beta-Ni (OH) 2 beta-NiOOH polyaniline composite electrode and preparation method and application thereof - Google Patents

Abstract

The invention relates to a beta-Ni (OH) ₂ A/beta-NiOOH polyaniline composite electrode and a preparation method and application thereof belong to the field of super capacitors. beta-Ni (OH) ₂ The preparation method of the/beta-NiOOH polyaniline composite electrode comprises the following process steps: preparation of surface grown with beta-Ni (OH) ₂ A conductive substrate of the array; under a three-electrode system, with beta-Ni (OH) ₂ The array is a working electrode, a metal material or a carbon material is used as a counter electrode, a saturated calomel electrode, an Ag/AgCl electrode or an HgO/Hg electrode is used as a reference electrode, and beta-Ni (OH) is prepared in an aqueous solution of chloride, ethanol and aniline by cyclic voltammetry ₂ a/beta-NiOOH polyaniline composite electrode. The preparation method is simple and can be used for large-scale production, and the prepared electrode is applied to the super capacitor, has high specific capacity and excellent cycle stability.

Description

A kind of β-Ni(OH)2/β-NiOOH polyaniline composite electrode and its preparation method and application

technical field

The invention relates to a β-Ni(OH) ₂ /β-NiOOH polyaniline composite electrode and a preparation method and application thereof, belonging to the field of supercapacitors.

Background technique

With the development of the economy and the continuous improvement of people's living standards, the problems of environmental pollution and climate change have been paid more and more attention by the state in recent years. In order to reduce smog and cope with global warming, it is necessary to control the consumption of fossil energy and replace it with clean energy such as wind energy and tides. These energies must be transmitted or stored in the form of electrical energy. Therefore, in recent years, different forms of batteries such as lithium-ion batteries, fuel cells, lead storage batteries, and hydrogen batteries have received great attention. However, the power density of batteries is generally low, which cannot meet the needs of high power output, such as the acceleration process of electric vehicles. Due to its high power density and ability to compensate for the defects of batteries, supercapacitors have attracted more and more attention. As a pseudocapacitive material, β-Ni(OH) ₂ has a large theoretical specific capacity, but compared with traditional carbon materials, its electrical conductivity is lower, which lowers its rate performance and its cycle stability is slightly worse. Therefore, it is particularly important to modify the structure and surface of β-Ni(OH) ₂ , which can effectively improve the cycle performance of β-Ni(OH) ₂ .

Contents of the invention

In the present invention, through a simple synthetic route at room temperature and assisted by electrochemical means, aniline is polymerized onto the surface of β-Ni(OH) ₂ while regulating the charge ratio in β-Ni(OH) ₂ to obtain a β-Ni(OH) 2 Ni(OH) ₂ /β-NiOOH polyaniline composite electrode. The present invention obtains Ni(OH) ₂ array by solution immersion method, β-Ni(OH) ₂ electrode is oxidized and compounded with polyaniline by electrochemical oxidation deposition method, can provide a kind of simple and effective preparation β-Ni(OH) ) ₂ /β-NiOOH polyaniline composite electrode, the resulting β-Ni(OH) ₂ /β-NiOOH polyaniline composite electrode has great application prospects.

The purpose of the present invention is to solve the technical problem of poor cycle stability of existing supercapacitors, and provide a β-Ni(OH) ₂ /β-NiOOH polyaniline composite electrode and its preparation method and application.

A method for preparing a β-Ni(OH) ₂ /β-NiOOH polyaniline composite electrode, comprising the following process steps:

(1) Prepare a conductive substrate with β-Ni(OH) ₂ arrays grown on its surface; (2) Under the three-electrode system, use the conductive substrate with β-Ni(OH) ₂ arrays grown on the surface obtained in step (1) as the work Electrode, with metal material or carbon material as counter electrode, saturated calomel electrode, Ag/AgCl electrode or HgO/Hg electrode as reference electrode, in the aqueous solution of chloride, ethanol and aniline, prepare β- Ni(OH) ₂ /β-NiOOH polyaniline composite electrode, wherein the chloride concentration is 0.5-3mol/L, the aniline concentration is 2-5mg/L, and the volume ratio of ethanol to water is 1:20

In the above technical scheme, the preparation method of the β-Ni(OH) ₂ array is not particularly limited, and the room temperature chemical solution method, hydrothermal method, solvothermal method, chemical deposition method or electrodeposition method well known to those skilled in the art are used That is, the chemical solution method at room temperature is preferred.

Preferably, the nickel conductive substrate is completely immersed in hydrochloric acid with a concentration of 0.01 to 13 mol/L and ultrasonically oscillated for 5 to 30 minutes, rinsed repeatedly with deionized water and soaked in deionized water for several days to obtain β-Ni ( OH) Conductive substrate of _{the array} ;

Further, the nickel conductive substrate is completely immersed in hydrochloric acid with a concentration of 0.01-13mol/L and ultrasonically oscillated for 5-30 minutes, rinsed repeatedly with deionized water, and then soaked in deionized water for seven days, that is, β-Ni(OH) grown on the surface ) ₂ arrays of conductive substrates.

In the above technical solution, the amount of hydrochloric acid is enough to fully immerse the nickel conductive substrate therein.

In the above technical solution, the purity of the aniline is greater than 99%; the purity of the hydrochloric acid is >99.5%.

In the above technical solution, the nickel conductive substrate is a nickel conductive substrate, preferably nickel foam.

In the above technical solution, the electrodeposition conditions are preferably as follows: under the three-electrode system, cycle 10 to 20 cycles in the cyclic voltammetry mode at a scanning speed of 5 to 50 mV/s, and the potential range is ∼1.2 to 1.0 V relative to saturation. mercury electrode.

In the above technical solution, preferably the chloride is potassium chloride or sodium chloride.

In the above technical solution, preferably, the counter electrode is a Pt sheet, Pt wire, Pt mesh, carbon cloth, carbon paper, foam, copper mesh, titanium mesh, stainless steel mesh or titanium sheet.

Another object of the present invention is to provide a β-Ni(OH) ₂ /β-NiOOH polyaniline composite electrode prepared by the above method.

A β-Ni(OH) ₂ /β-NiOOH polyaniline composite electrode is prepared as follows:

(1) Completely immerse the nickel conductive substrate in hydrochloric acid with a concentration of 0.01-13mol/L and ultrasonically vibrate for 5-30 minutes, rinse it repeatedly with deionized water, and then soak it in deionized water for several days to obtain β-Ni ( OH) Conductive substrate of _{the array} ;

(2) Under the three-electrode system, the conductive substrate with the β-Ni(OH) ₂ array grown on the surface obtained in step (1) is used as the working electrode, and the metal material or carbon material is used as the counter electrode, saturated calomel electrode, Ag/ The AgCl electrode or the HgO/Hg electrode is used as a reference electrode, and the β-Ni(OH) ₂ /β-NiOOH polyaniline composite electrode is prepared by cyclic voltammetry in an aqueous solution of chloride, ethanol and aniline, wherein the chlorine The compound concentration is 0.5-3mol/L, the aniline concentration is 2-5mg/L, and the volume ratio of ethanol to water is 1:20.

Another object of the present invention is to provide the application of the above-mentioned β-Ni(OH) ₂ /β-NiOOH polyaniline composite electrode in supercapacitors.

The beneficial effect of the present invention is: the present invention provides a kind of β-Ni(OH) ₂ /β-NiOOH polyaniline electrode and its preparation method and application, this electrode is to prepare β-Ni(OH) ₂ array first; β-Ni(OH) ₂ /β-NiOOH polyaniline arrays are prepared by electrochemical method of Ni(OH) ₂ arrays; the above preparation method is simple and can be mass-produced, and the prepared electrodes are used in supercapacitors with high specific capacity , and has excellent cycle stability.

Description of drawings

Figure 1 is a scanning electron micrograph of the β-Ni(OH) ₂ /β-NiOOH polyaniline array prepared in Example 1;

Fig. 2 is the beta-Ni (OH) that embodiment ₁ prepares The scanning electron micrograph figure of array;

Fig. 3 is the cycle curve of the β-Ni(OH) ₂ /β-NiOOH polyaniline electrode.

Detailed ways

The following non-limiting examples can enable those skilled in the art to understand the present invention more fully, but do not limit the present invention in any way.

Step 1: preparing a conductive substrate with β-Ni(OH) _arrays grown on the surface;

Step 2: Prepare the β-Ni(OH) ₂ /β-NiOOH polyaniline array by electrochemical cyclic voltammetry from the β-Ni(OH) ₂ array prepared in step 1;

According to the present invention, a conductive substrate with a β-Ni(OH) ₂ array grown on the surface is first prepared, and the preparation method of the β-Ni(OH) ₂ array is not particularly limited, and the room temperature chemical solution method well known to those skilled in the art is adopted, Hydrothermal method, solvothermal method, chemical deposition method or electrodeposition method can be used, preferably room temperature chemical solution method.

The room temperature chemical solution method is preferably in 1mol/L HCl aqueous solution, the conductive substrate (foam nickel) is ultrasonically treated for 30 minutes; then the substrate is rinsed 3 times with deionized water, and then soaked for a week to obtain β-Ni(OH) ₂ array. The conductive substrate can only be a nickel substrate.

According to the present invention, β-Ni(OH) ₂ /β-NiOOH polyaniline arrays are prepared by the β-Ni(OH) ₂ array prepared above by electrochemical oxidation deposition method; specifically, the obtained Ni(OH) ₂ The array is used as the working electrode, the saturated calomel electrode is used as the reference electrode, and the platinum wire is used as the counter electrode. In 1mol/L KCl, 5mg/L aniline water-ethanol (20:1) mixture, at a scan rate of 5mV/s , using cyclic voltammetry to cycle 5 cycles in the potential range of -1.2 to 1.0 V to obtain a polyaniline array of β-Ni(OH) ₂ /β-NiOOH.

The present invention also provides the β-Ni(OH) ₂ /β-NiOOH polyaniline array electrode prepared by the above method.

The present invention also provides the application of the above-mentioned β-Ni(OH) ₂ /β-NiOOH polyaniline electrode in a supercapacitor, and the above-mentioned β-Ni(OH) ₂ /β-NiOOH polyaniline is used as the cathode and the platinum sheet is used as the anode to assemble the whole Battery, using CHI660E electrochemical workstation to test its supercapacitor performance in alkaline electrolyte.

The present invention will be described in further detail below in conjunction with the examples, and the raw materials involved in the examples are all commercially available.

Example 1

Put 1cm×3cm foam nickel in 50ml of 1mol/L HCl aqueous solution, ultrasonic treatment for 30 minutes; after that, the substrate was rinsed with deionized water for 3 times, and then soaked for a week to obtain β-Ni(OH) ₂ arrays grown on the surface. conductive substrate. Figure 2 is a scanning electron micrograph of the β-Ni(OH) ₂ array prepared in Example 1, which shows that the nickel foam is completely covered by β-Ni(OH) ₂ .

Example 2

The surface growth that embodiment 1 obtains has β-Ni (OH) Conductive substrate of array as working electrode, saturated calomel electrode as reference electrode, platinum _wire as counter electrode, in 1mol/LKCl, 5mg/L aniline water- In ethanol (20:1) mixture, at a scan rate of 5mV/s, by cyclic voltammetry, cycle 5 times in the potential range of -1.2 to 1.0V, that is, β-Ni(OH) ₂ /β- NiOOH polyaniline array.

Figure 1 is a scanning electron micrograph of the β-Ni(OH) ₂ /β-NiOOH polyaniline array prepared in Example 2, which shows that the nickel foam is completely covered by the composite array. Figure 3 is the cycle curve of the β-Ni(OH) ₂ /β-NiOOH polyaniline electrode. It can be seen that its highest specific capacitance value can reach 1000F/g, and after 1000 cycles, there is still a retention value of 500F/g.

Example 3

Put 1cm×3cm foam nickel in 50ml 2mol/L HCl aqueous solution, ultrasonic treatment for 30 minutes; after that, the substrate was washed 3 times with deionized water, and then soaked for a week to obtain β-Ni(OH) ₂ arrays grown on the surface. conductive substrate.

Example 4

The surface growth that embodiment ₃ obtains has β-Ni (OH) The conduction substrate of array is working electrode, and saturated calomel electrode is as reference electrode, and platinum wire is as counter electrode, in 1mol/LKCl, 5mg/L aniline water- In ethanol (20:1) mixed solution, at a scan rate of 5mV/s, by cyclic voltammetry, cycle 10 times in the potential range of -1.2 to 1.0V, that is, β-Ni(OH) ₂ /β- NiOOH polyaniline array.

Example 5

Put 1cm×3cm foam nickel in 50ml of 1mol/L HCl aqueous solution, ultrasonic treatment for 30 minutes; after that, the substrate was rinsed with deionized water for 3 times, and then soaked for a week to obtain β-Ni(OH) ₂ arrays grown on the surface. conductive substrate.

The obtained surface is grown with β-Ni(OH) The conductive substrate of array is used as working electrode, and _saturated calomel electrode is used as reference electrode, and platinum wire is used as counter electrode, in 1mol/LKCl, 5mg/L aniline water-ethanol (20 :1) In the mixed solution, at a scan rate of 10mV/s, cyclic voltammetry is used to cycle 5 times in the potential range of -1.2 to 1.0V to obtain β-Ni(OH) ₂ /β-NiOOH polyaniline array.

Example 6

Put 1cm×3cm foam nickel in 50ml of 1mol/L HCl aqueous solution, ultrasonic treatment for 30 minutes; after that, the substrate was rinsed with deionized water for 3 times, and then soaked for a week to obtain β-Ni(OH) ₂ arrays grown on the surface. conductive substrate.

The obtained surface growth has β-Ni (OH) Conductive substrate of _array as working electrode, saturated calomel electrode as reference electrode, nickel foam as counter electrode, in 1mol/LKCl, 5mg/L aniline water-ethanol (20 :1) In the mixed solution, at a scan rate of 5mV/s, cyclic voltammetry is used to cycle 5 times in the potential range of -1.2 to 1.0V to obtain β-Ni(OH) ₂ /β-NiOOH polyaniline array.

Example 7

Put 1cm×3cm foam nickel in 50ml of 1mol/L HCl aqueous solution, ultrasonic treatment for 30 minutes; after that, the substrate was rinsed with deionized water for 3 times, and then soaked for a week to obtain β-Ni(OH) ₂ arrays grown on the surface. conductive substrate.

The obtained surface growth has β-Ni (OH) Conductive substrate of _array as working electrode, Ag/AgCl electrode is as reference electrode, and platinum wire is as counter electrode, in 1mol/L KCl, 5mg/L aniline water-ethanol ( 20:1) in the mixed solution, under the scan rate of 5mV/s, by cyclic voltammetry, cycle 5 times in the potential range of -1.2 ~ 1.0V, that is, β-Ni(OH) ₂ /β-NiOOH polymer Aniline array.

Example 8

A nickel sheet of 1 cm × 3 cm was placed in 50 ml of 1mol/L HCl aqueous solution, and ultrasonically treated for 30 minutes; then the substrate was rinsed with deionized water three times, and then soaked for a week to obtain a β-Ni(OH) ₂ array grown on the surface. conductive substrate.

The obtained surface growth has β-Ni (OH) Conductive substrate of array as working electrode, _saturated calomel electrode as reference electrode, platinum wire as counter electrode, in 1mol/L KCl, 5mg/L aniline water-ethanol ( 20:1) in the mixed solution, at a scan rate of 10mV/s, by cyclic voltammetry, cycled 5 times in the potential range of -1.2 to 1.0V to obtain β-Ni(OH) ₂ /β-NiOOH polymer Aniline array.

Example 9

Put a 1cm×3cm nickel foam in 100ml of 1mol/L HCl aqueous solution, and ultrasonically treat it for 30 minutes; then rinse the substrate with deionized water for 3 times, and then soak it for a week to obtain a substrate with β-Ni(OH) ₂ arrays grown on the surface. conductive substrate.

The obtained surface growth has β-Ni (OH) Conductive substrate of array as working electrode, _saturated calomel electrode as reference electrode, platinum wire as counter electrode, in 1mol/L KCl, 5mg/L aniline water-ethanol ( 20:1) in the mixed solution, under the scan rate of 5mV/s, by cyclic voltammetry, cycle 5 times in the potential range of -1.2 ~ 1.0V, that is, β-Ni(OH) ₂ /β-NiOOH polymer Aniline array.

Claims (8)

1. beta-Ni (OH) ₂ The preparation method of the/beta-NiOOH polyaniline composite electrode is characterized by comprising the following steps: the method comprises the following process steps:

(1) Preparation of surface grown with beta-Ni (OH) ₂ A conductive substrate of the array;

(2) Under a three-electrode system, the surface obtained in the step (1) is grown with beta-Ni (OH) ₂ The conductive substrate of the array is a working electrode, a metal material or a carbon material is used as a counter electrode, a saturated calomel electrode, an Ag/AgCl electrode or an HgO/Hg electrode is used as a reference electrode, and beta-Ni (OH) is prepared in an aqueous solution of chloride, ethanol and aniline by a cyclic voltammetry method ₂ The/[ beta ] -NiOOH polyaniline composite electrode is characterized in that the chloride concentration is 0.5-3 mol/L, the aniline concentration is 2-5 mg/L, and the volume ratio of ethanol to water is 1.

2. The method of claim 1, wherein: completely immersing the nickel conductive substrate into hydrochloric acid with the concentration of 0.01-13 mol/L for ultrasonic oscillation for 5-30 minutes, repeatedly washing the nickel conductive substrate with deionized water, and soaking the nickel conductive substrate in the deionized water for a plurality of days to obtain the nickel conductive substrate with beta-Ni (OH) growing on the surface ₂ A conductive substrate of the array.

3. The method of claim 2, wherein: the nickel conductive substrate is foamed nickel.

4. The method of claim 1, wherein: the electrodeposition conditions were: under a three-electrode system, the electrode is cycled for 10 to 20 circles under a cyclic voltammetry mode at a scanning speed of 5mV/s, and the potential range is-1.2 to 1.0V relative to a saturated calomel electrode.

5. The method of claim 1, wherein: the chloride is potassium chloride or sodium chloride.

6. The method of claim 1, wherein: the counter electrode is a Pt sheet, a Pt wire, a Pt net, carbon cloth, carbon paper, foam, a copper net, a titanium net, a stainless steel net or a titanium sheet.

7. beta-Ni (OH) obtainable by the process according to any one of claims 1 to 6 ₂ a/beta-NiOOH polyaniline composite electrode.

8. The beta-Ni (OH) of claim 7 ₂ The application of the/beta-NiOOH polyaniline composite electrode in the aspect of a super capacitor.

Images