CN113437312A

CN113437312A - Preparation of Prussian blue derivative catalyst applied to zinc-air battery

Info

Publication number: CN113437312A
Application number: CN202110707065.XA
Authority: CN
Inventors: 李光达; 张广辉; 赵凌雪
Original assignee: Qilu University of Technology
Current assignee: Qilu University of Technology
Priority date: 2021-06-24
Filing date: 2021-06-24
Publication date: 2021-09-24

Abstract

The invention belongs to the field of nano materials and electrocatalysis, and particularly relates to a preparation method of a Prussian blue derivative catalyst applied to a zinc-air battery. Synthesizing a rod-shaped nickel hydroxide substrate by a simple hydrothermal method, and then further synthesizing by taking nickel hydroxide as a substrate through hydrothermal to obtain a final product: nickel hydroxide/nickel cobalt prussian blue derivative material. The nickel hydroxide/nickel cobalt Prussian blue derivative catalyst material has an OER overpotential (310mV) smaller than that of a noble metal catalyst, can be assembled into a zinc-air battery for a long time (500 circles) and is stable in circulation, and the catalyst has the advantages of simple preparation process, rich and cheap raw materials, extremely short synthesis period, high yield and the like.

Description

Preparation of Prussian blue derivative catalyst applied to zinc-air battery

Technical Field

The invention belongs to the field of nano materials and electrocatalysis, and particularly relates to preparation of a Prussian blue derivative catalyst applied to a zinc-air battery.

Background

Among the various electrochemical energy storage and conversion systems, zinc-air batteries have been extensively studied in recent years due to their high theoretical energy and power densities, reliable safety, and economic viability. In order to develop a portable zinc-air battery having high performance, an air cathode material that realizes excellent bifunctional oxygen reactivity, strong alkali resistance, flexibility, and ductility is particularly important. In all high activityAmong the agents, they show low overpotentials and excellent stability, but insufficient bifunctional catalytic performances and high costs (content in earth crust of only 9X 10)^-9%) still limits their large-scale commercial use. Therefore, there is an urgent need to develop highly efficient and stable non-noble metal catalysts.

Researchers have found that transition metal-based oxyhydroxide (LDH) has been a promising non-noble metal bifunctional electrocatalyst in alkaline electrolyte solutions due to its specific two-dimensional 2D structure, large surface area, adjustable composition and abundant active sites with an effective and promising potential to replace noble metal catalysts. Nevertheless, the catalytic performance of transition metal based LDHs is still limited by their low conductivity and slow oxygen reduction process. Here, we propose a simple template chemical etching/anion exchange reaction method to synthesize bimetallic cubic nanostructured prussian blue derivative (PBA).

In the invention, NiCoPBA is taken as an example, and the precursor of LDH is Ni (OH) which is cheap and easily available₂The chemical etching selects potassium cobalt cyanide, successfully demonstrates the concept that the two-dimensional nano-sheet Ni (OH)₂The synthesis and wide application of the cubic NiCoPBA.

Disclosure of Invention

According to the problems provided by the invention, the invention provides a preparation method of a zinc air battery negative electrode material NiCoPBA, so that the problem of circulation stability caused by volume expansion of the negative electrode material of the zinc air battery is solved, and the high-specific-capacity electrode material is provided for the zinc air battery.

The specific scheme of the invention is as follows:

(1) dissolving a certain amount of nickel dichloride hexahydrate, ammonium fluoride and urea in a certain amount of deionized water, magnetically stirring for 15 minutes, transferring the mixed solution into a reaction kettle, reacting for 12 hours at 100 ℃, and centrifugally drying.

(2) Dissolving a certain amount of potassium cobalt cyanide in a certain amount of deionized water, then dispersing the product obtained in the step (1), magnetically stirring for 12 hours, and centrifugally drying.

First of allIn step (2), 0.328g of nickel dichloride hexahydrate, 0.178g of ammonium fluoride and 0.364g of urea were dissolved in 25mL of deionized water, magnetically stirred for 15 minutes, and then the above mixture was transferred to a 40mL reaction vessel and reacted at 100 ℃ for 12 hours. After the reaction is finished, the obtained product is respectively washed by deionized water and absolute ethyl alcohol in a centrifugal mode for 3 times, and is dried for 12 hours in an oven at the temperature of 60 ℃. Thus obtaining Ni (OH)₂And (3) precursor.

In the second step, 0.1g of the product in the step (1) is dissolved in potassium cobalt cyanide solution, magnetic stirring is carried out for 12 hours, after the reaction is finished, the obtained product is respectively washed centrifugally for 3 times by deionized water and absolute ethyl alcohol, and is dried for 12 hours in an oven at 60 ℃ to obtain Ni (OH)₂a/NiCoPBA catalyst.

Drawings

FIG. 1 shows Ni (OH) prepared in the example of the embodiment₂X-ray diffraction pattern of the precursor.

FIG. 2 shows nanometer Ni (OH) prepared in the example of the embodiment₂X-ray diffraction pattern of/NiCoPBA catalyst material.

FIG. 3 shows the nano-Ni (OH) prepared in the embodiment₂Transmission electron microscopy images of/NiCoPBA catalyst materials.

FIG. 4 shows the nano-Ni (OH) prepared in the embodiment example₂Polarization curves of oxygen evolution reactions measured with NiCoPBA catalyst material under 0.1M potassium hydroxide basic conditions.

FIG. 5 shows the nano-Ni (OH) prepared in the embodiment example₂Polarization curves of oxygen reduction reactions measured with NiCoPBA catalyst material under 0.1M potassium hydroxide basic conditions.

FIG. 6 shows the nano-Ni (OH) prepared in the embodiment example₂Zinc air battery assembled by/NiCoPBA catalyst material at current density of 10mA cm^-2The cycle stability of (c).

Detailed Description

The following patent of the present invention is described in detail with reference to specific experimental schemes for further understanding of the present invention, and the following specific examples are not limited to one experimental scheme.

Examples

(1) 0.328g of nickel dichloride hexahydrate, 0.178g of ammonium fluoride and 0.364g of urea were dissolved in 25mL of deionized water, magnetically stirred for 15 minutes, and then the mixture was transferred to a 40mL reaction vessel and reacted at 100 ℃ for 12 hours. After the reaction is finished, the obtained product is respectively washed by deionized water and absolute ethyl alcohol in a centrifugal mode for 3 times, and is dried for 12 hours in an oven at the temperature of 60 ℃. Then dissolving 0.1g of the product in potassium cobalt cyanide solution, magnetically stirring for 12 hours, after the reaction is finished, centrifugally washing the obtained product with deionized water and absolute ethyl alcohol for 3 times respectively, and drying in an oven at 60 ℃ for 12 hours to obtain Ni (OH)₂A/NiCoPBA product.

(2) The electrode manufacturing process comprises the following steps:

weigh 2 mg of Ni (OH)₂the/NiCoPBA catalyst material, 2 mg acetylene black and 5. mu.l Nafion were dissolved in 500. mu.l isopropanol, sonicated for 20 minutes, 10. mu.l of the slurry was applied dropwise to a glassy carbon electrode and dried at room temperature for 12 hours.

And (3) testing oxygen precipitation and oxygen reduction performance:

with nano Ni (OH)₂The performance test of the/NiCoPBA catalyst material is characterized in that: when oxygen precipitation performance analysis is carried out, the electrolyte is 1.0M potassium hydroxide solution, nitrogen is introduced for half an hour before testing, the solution is ensured to be oxygen-free, and the scanning speed is 5 mV/s. Test data show, nanometer Ni (OH)₂the/NiCoPBA catalyst material is at 10mA cm^-2The overpotential at current density of (a) is only 310 mV. When oxygen evolution performance analysis is carried out, the electrolyte is 0.1M potassium hydroxide solution, oxygen is introduced for half an hour before testing, the solution is fully filled with oxygen, the rotating speed of the glassy carbon electrode is 1600r/min, and the scanning speed is 5 mV/s. Test data show, nanometer Ni (OH)₂the/NiCoPBA catalyst material has a half-wave potential of 0.72V.

As shown in FIG. 1, Ni (OH)₂The X-ray diffraction pattern of the precursor completely corresponds to the standard PDF card.

As shown in FIG. 2, the final product obtained is cubic Ni (OH)₂The X-ray diffraction pattern of/NiCoPBA corresponds exactly to the standard PDF card for cobalt disulfide.

As shown in FIG. 3, cubic Ni (OH)₂Transmission electron microscopy image of/NiCoPBA from which cubic Ni (OH) can be derived₂the/NiCoPBA composite is cuboidal.

As shown in FIG. 4, the oxygen evolution catalysis curve measured under alkaline conditions was measured at a current density of 10mA cm^-2The overpotential is only 310 mV.

As shown in FIG. 5, the half-wave potential of the oxygen evolution catalyst curve measured under alkaline conditions was 0.72V.

As shown in FIG. 6, the zinc-air cell was operated at a current density of 10mA cm^-2And next, the circulation can be stabilized for 500 circles.

Claims

1. A kind of Ni (OH)₂The preparation method of the/NiCoPBA catalyst material is characterized by comprising the following steps: the catalyst is prepared by taking potassium cobalt cyanide and nickel salt as raw materials through a hydrothermal method.

2. The preparation process of the nano NiCoPBA catalyst material comprises the following steps:

in the first step, 0.328g of nickel dichloride hexahydrate, 0.178g of ammonium fluoride and 0.364g of urea were dissolved in 25mL of deionized water, magnetically stirred for 15 minutes, and then the mixture was transferred to a 40mL reaction vessel and reacted at 100 ℃ for 12 hours. After the reaction is finished, the obtained product is respectively washed by deionized water and absolute ethyl alcohol in a centrifugal mode for 3 times, and is dried for 12 hours in an oven at the temperature of 60 ℃. Thus obtaining Ni (OH)₂And (3) precursor.

3. The hydrothermal process of claim 1, wherein the hydrothermal process comprises Ni (OH)₂Cubic particles of/NiCoPBA.

4. The high efficiency oxygen evolution/oxygen reduction catalyst as set forth in claim 2, comprising Ni (OH)₂And NiCoPBA.

5. The compound of claim 2, in the form of Ni (OH)₂The NiCoPBA is matrix NiCoPBA, and the nickel salt can be nickel nitrate or nickel chloride.