A Ru-Cu amorphous nano alloy for lithium carbon dioxide battery cathode catalyst and preparation method thereof

Abstract

The present invention discloses a Ru-Cu amorphous nano-alloy for a lithium carbon dioxide battery cathode catalyst and a preparation method thereof, wherein the morphology is a lamellar nanostructure with a thickness of 5 to 100 nm. The preparation method is as follows: ruthenium acetylacetonate, copper acetylacetonate and potassium bromide are dissolved in a mixed solution of ethanol and water to obtain a light red liquid after complete dissolution; the liquid is dried at 80 to 100 ° C for 8 to 16 hours to obtain a solid powder; in an air atmosphere, calcined at 260 to 280 ° C for 60 to 120 minutes, followed by natural cooling; finally, it is obtained by grinding, washing and drying. The Ru-Cu amorphous nano-alloy obtained by the present invention can be used to prepare a lithium carbon dioxide battery cathode, which can greatly increase the decomposition rate of lithium carbonate, solve the key problems such as high charging voltage and low energy efficiency of lithium carbon dioxide batteries, and achieve the purpose of improving the charge and discharge performance of lithium carbon dioxide batteries.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium carbon dioxide batteries, and in particular relates to a Ru-Cu amorphous nano alloy used as a cathode catalyst for lithium carbon dioxide batteries and a preparation method thereof. Background Art

[0002] Lithium carbon dioxide batteries are a type of metal-air battery and are a new type of energy conversion and storage device. The principle of lithium carbon dioxide batteries is to capture carbon dioxide greenhouse gas in the air as a reactant through the positive electrode, and undergo an oxidation-reduction reaction with the metal Li from the negative electrode on the electrode surface, thereby simultaneously achieving the capture of carbon dioxide gas and clean energy output. Compared with traditional lithium batteries, the new lithium carbon dioxide battery can provide higher energy density and extend the battery life of the device. On the other hand, compared with traditional carbon capture technology, the new lithium carbon dioxide battery can directly convert carbon dioxide greenhouse gas into clean electricity, avoiding other intermediate conversion steps and greatly improving the efficiency of carbon capture. Therefore, lithium carbon dioxide batteries are considered to be the next major new clean energy device to be developed.

[0003] However, the development of lithium-carbon dioxide batteries is still in its early stages, and many scientific challenges remain to be addressed. For example, the discharge process of lithium-carbon dioxide batteries produces lithium carbonate as a discharge product. Lithium carbonate is a wide-bandgap insulator with very sluggish electrochemical oxidation decomposition kinetics, which increases the charging voltage of lithium-carbon dioxide batteries, seriously affecting their energy efficiency and service life. Summary of the Invention

[0004] Technical problems solved: In response to the above technical problems, the present invention provides a Ru-Cu amorphous nano-alloy for lithium carbon dioxide battery positive electrode catalyst and its preparation method, which can greatly increase the decomposition rate of lithium carbonate, solve the key problems of high charging voltage and low energy efficiency of lithium carbon dioxide batteries, and achieve the purpose of improving the charge and discharge performance of lithium carbon dioxide batteries.

[0005] Technical solution: A Ru-Cu amorphous nanoalloy used as a cathode catalyst for lithium-carbon dioxide batteries, which has a lamellar nanostructure with a thickness of 5 to 100 nm.

[0006] The preparation method of Ru-Cu amorphous nano alloy has the following steps:

[0007] Step 1. Preparing a precursor solution: Dissolve ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide in a mixed solution of ethanol and water to obtain a light red liquid after complete dissolution. The concentrations of ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide are 0.45-0.92 g / L, 0.3-0.6 g / L, and 2.14 g / L, respectively. The volume ratio of ethanol to water in the mixed solution is 6:1.

[0008] Step 2. Drying: Dry the light red liquid obtained in step 1 at 80-100°C for 8-16 hours to obtain a solid powder;

[0009] Step 3. Calcination: Calcine the solid powder obtained in step 2 at 260-280° C. for 60-120 minutes under air atmosphere, and then cool naturally;

[0010] Step 4: Grind, wash and dry the material obtained in step 3 to obtain the Ru-Cu amorphous nano alloy.

[0011] Preferably, the washing solvent in step 4 is an ethanol aqueous solution.

[0012] Application of Ru-Cu amorphous nanoalloy in the preparation of positive electrode for lithium carbon dioxide batteries.

[0013] Beneficial effects: The bimetallic Ru-Cu amorphous nano-alloy material prepared by the present invention has excellent catalytic activity and stability. When used as a positive electrode catalyst for lithium carbon dioxide batteries, it can significantly increase the decomposition rate of lithium carbonate, solve the key problems of high charging voltage and low energy efficiency of lithium carbon dioxide batteries, and achieve the purpose of improving the charge and discharge performance of lithium carbon dioxide batteries. Figures 3-5 The figure shows the charge and discharge curves of the lithium carbon dioxide battery based on Ru1Cu2, Ru1Cu1 and Ru2Cu1 amorphous nano-alloys prepared in the present invention. According to the charge and discharge performance curves, the charging voltage (500 mAh / g) of the lithium carbon dioxide battery based on Ru1Cu2, Ru1Cu1 and Ru2Cu1 amorphous nano-alloys is reduced to 3.82, 3.75 and 3.89 V, respectively, which is better than the charging voltage (3.93 V) of the lithium carbon dioxide battery based on single metal Ru amorphous nano-materials under the same conditions ( Figure 6 ). BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is the XRD pattern of Ru1Cu2, Ru1Cu1 and Ru2Cu1 amorphous nanoalloys in Examples 1 to 3;

[0015] Figure 2 This is a scanning electron microscope image based on Ru1Cu1 amorphous nanoalloy;

[0016] Figure 3This is the charge and discharge curve of the lithium-carbon dioxide battery based on Ru1Cu2 amorphous nano-alloy;

[0017] Figure 4 This is the charge and discharge curve of the lithium-carbon dioxide battery based on Ru1Cu1 amorphous nano-alloy;

[0018] Figure 5 This is the charge and discharge curve of the lithium-carbon dioxide battery based on Ru2Cu1 amorphous nano-alloy;

[0019] Figure 6 This is the charge and discharge curve of a lithium-carbon dioxide battery based on single-metal Ru amorphous nanomaterials. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1

[0022] Step 1. Prepare the precursor solution: Dissolve ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide in a mixture of ethanol and water to obtain a light red liquid after complete dissolution. The concentrations of ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide are 0.45 g / L, 0.6 g / L, and 2.14 g / L, respectively. The volume ratio of ethanol to water in the mixture is 6:1.

[0023] Step 2. Drying: Place the light red liquid obtained in step 1 in an electric blast drying oven at 80°C for 12 hours to obtain a solid powder;

[0024] Step 3. Calcination: The solid powder obtained in step 2 was placed on a magnetic boat and calcined at 275°C for 90 minutes in an air atmosphere, and then naturally cooled to room temperature;

[0025] Step 4. Grind the material obtained in step 3 into fine powder, then wash it several times with a mixed solution of deionized water and ethanol, and then dry it to obtain Ru1Cu2 amorphous nano-alloy.

[0026] The XRD pattern of the bimetallic Ru1Cu2 amorphous nano-alloy material obtained in this embodiment is as follows: Figure 1 As shown, no diffraction characteristic peaks were observed, indicating that Ru1Cu2 is an amorphous material. The bimetallic Ru1Cu2 amorphous nano-alloy material in this embodiment was used as a positive electrode catalyst and assembled into a lithium carbon dioxide battery. The charge and discharge performance of the obtained lithium carbon dioxide battery is shown in FIG. Figure 3 As shown. Figure 3 The test results show that the charging voltage of the lithium carbon dioxide battery based on Ru1Cu2 amorphous nano-alloy is 3.82V, which is lower than the charging voltage of the lithium carbon dioxide battery based on single metal Ru amorphous nano-material (3.93 V) under the same conditions ( Figure 6 ), indicating that Ru1Cu2 amorphous nanoalloy can significantly increase the decomposition rate of lithium carbonate and improve the charge and discharge performance of lithium-carbon dioxide batteries.

[0027] Example 2

[0028] Step 1. Precursor solution preparation: Dissolve ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide in a mixture of ethanol and water to obtain a light red liquid after complete dissolution. The concentrations of ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide are 0.72 g / L, 0.42 g / L, and 2.14 g / L, respectively. The volume ratio of ethanol to water in the mixture is 6:1.

[0029] Step 2. Drying: Place the light red liquid obtained in step 1 in an electric blast drying oven at 80°C for 12 hours to obtain a solid powder;

[0030] Step 3. Calcination: The solid powder obtained in step 2 was placed on a magnetic boat and calcined at 275°C for 90 minutes in an air atmosphere, and then naturally cooled to room temperature;

[0031] Step 4. Grind the material obtained in step 3 into fine powder, then wash it several times with a mixed solution of deionized water and ethanol, and then dry it to obtain Ru1Cu1 amorphous nano-alloy.

[0032] The XRD pattern of the bimetallic Ru1Cu1 amorphous nano-alloy material obtained in this embodiment is as follows: Figure 1 As shown in Figure 2, no diffraction characteristic peaks were observed, indicating that Ru1Cu1 is an amorphous material. Figure 2 The figure shows a scanning electron microscope image of Ru1Cu1 amorphous nano-alloy. It can be seen from the figure that the morphology of Ru1Cu1 amorphous nano-alloy is a lamellar nanostructure with a thickness of 5-100nm. The bimetallic Ru1Cu1 amorphous nano-alloy material in this embodiment is used as a positive electrode catalyst and assembled into a lithium carbon dioxide battery. The charge and discharge performance of the obtained lithium carbon dioxide battery is shown in FIG. Figure 4 As shown. Figure 4 The test results show that the charging voltage of the lithium carbon dioxide battery based on Ru1Cu1 amorphous nano-alloy is 3.75 V, which is lower than the charging voltage of the lithium carbon dioxide battery based on single metal Ru amorphous nano-material (3.93 V) under the same conditions ( Figure 6 ), indicating that Ru1Cu1 amorphous nanoalloy can significantly increase the decomposition rate of lithium carbonate and improve the charge and discharge performance of lithium-carbon dioxide batteries.

[0033] Example 3

[0034] Step 1. Preparation of precursor solution: Dissolve ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide in a mixed solution of ethanol and water to obtain a light red liquid after complete dissolution. The concentrations of ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide are 0.92 g / L, 0.3 g / L, and 2.14 g / L, respectively. The volume ratio of ethanol to water in the mixed solution is 6:1.

[0035] Step 2. Drying: Place the light red liquid obtained in step 1 in an electric blast drying oven at 80°C for 12 hours to obtain a solid powder;

[0036] Step 3. Calcination: The solid powder obtained in step 2 was placed on a magnetic boat and calcined at 275°C for 90 minutes in an air atmosphere, and then naturally cooled to room temperature;

[0037] Step 4. Grind the material obtained in step 3 into fine powder, then wash it several times with a mixed solution of deionized water and ethanol, and then dry it to obtain Ru2Cu1 amorphous nano-alloy.

[0038] The XRD pattern of the bimetallic Ru2Cu1 amorphous nano-alloy material obtained in this embodiment is as follows: Figure 1 As shown in Figure 2, no diffraction characteristic peaks were observed, indicating that Ru2Cu1 is an amorphous material. The bimetallic Ru2Cu1 amorphous nano-alloy material in this embodiment was used as a positive electrode catalyst and assembled into a lithium carbon dioxide battery. The charge and discharge performance of the obtained lithium carbon dioxide battery is shown in Figure 2. Figure 5 As shown. Figure 5 The test results show that the charging voltage of the lithium carbon dioxide battery based on Ru2Cu1 amorphous nano-alloy is 3.89 V, which is lower than the charging voltage of the lithium carbon dioxide battery based on single metal Ru amorphous nano-material (3.93 V) under the same conditions ( Figure 6 ), indicating that Ru2Cu1 amorphous nanoalloy can significantly increase the decomposition rate of lithium carbonate and improve the charge and discharge performance of lithium-carbon dioxide batteries.

Claims

1. A method for preparing Ru-Cu amorphous nano alloy for lithium carbon dioxide battery cathode catalyst, characterized in that: Here are the steps: Step 1. Preparing a precursor solution: Dissolve ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide in a mixed solution of ethanol and water to obtain a light red liquid after complete dissolution. The concentrations of ruthenium acetylacetonate, copper acetylacetonate, and potassium bromide are 0.45-0.92 g / L, 0.3-0.6 g / L, and 2.14 g / L, respectively. The volume ratio of ethanol to water in the mixed solution is 6:

1. Step 2. Drying: Dry the light red liquid obtained in step 1 at 80-100°C for 8-16 hours to obtain a solid powder; Step 3. Calcination: Calcine the solid powder obtained in step 2 at 260-280° C. for 60-120 minutes under air atmosphere, and then cool naturally; Step 4: Grind, wash and dry the material obtained in step 3 to obtain the Ru-Cu amorphous nano alloy.

2. The method for preparing Ru-Cu amorphous nano alloy according to claim 1, characterized in that: The washing solvent in step 4 is ethanol aqueous solution.

3. The Ru-Cu amorphous nano alloy for lithium carbon dioxide battery cathode catalyst obtained by the preparation method of claim 1, characterized in that: Its morphology is a lamellar nanostructure with a thickness of 5~100nm.

4. Use of the Ru-Cu amorphous nano alloy according to claim 3 in preparing a positive electrode of a lithium carbon dioxide battery.

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