A method for increasing the particle size of copper hexacyanoferrite
The problem of preparing large-sized copper hexacyanoferrite particles was solved by electrochemical treatment, achieving controllable growth from nanometers to micrometers and improving the electrochemical performance of the particles.
Patent Information
- Application Number
- CN202311781481.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-22
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2043-12-22
AI Technical Summary
Existing technologies struggle to prepare large-sized copper hexacyanoferrite particles, especially micron-sized particles, as traditional methods lack a simple, controllable approach from nanometer to micron scale.
An electrochemical treatment method was adopted, in which a three-electrode system was used to alternately perform program A and program B in sulfuric acid solution, and the current density and time were controlled to increase the size of copper hexacyanoferrate particles. The specific steps included mixing CuHCF material with conductive agent and binder to form an electrode slurry, coating it on carbon fiber paper to form an electrode sheet, and then performing electrochemical treatment in sulfuric acid solutions of different concentrations.
The small CuHCF particles were successfully enlarged to 1-2 μm, and the particles exhibited a cubic morphology. The more cycles were performed, the larger the particle size became, which reduced the particle interface and improved the electrochemical performance.
Smart Images
Figure CN117756137B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of materials preparation and relates to a method for increasing the particle size of copper hexacyanoferrite. Background Technology
[0002] Copper hexacyanoferrite (CuHCF) has advantages such as low cost, simple preparation, and large-size channels, and is widely used in energy storage and conversion, gas adsorption, seawater desalination, and electrochromism. However, the preparation of large-size, especially micron-sized particles, remains a challenge.
[0003] CuHCF is often prepared via co-precipitation, which, due to its relatively fast nucleation rate, typically only yields small nanocrystals. While traditional methods can increase grain size to some extent by adding chelating agents or surfactants, a simple method for preparing controllable sizes, ranging from nanometers to micrometers, is still lacking. Summary of the Invention
[0004] This invention provides a method for increasing the particle size of copper hexacyanoferrite (CuHCF) material. Small-sized CuHCF particles are prepared into electrode sheets. Through a simple electrochemical treatment, small-sized (approximately 80 nm irregular particles) can be increased to 1-2 μm. Furthermore, by controlling the magnitude of the electrochemical treatment current and the treatment time, cubic morphologies of different sizes can be controllably formed.
[0005] This invention employs the following technical solution: a method for increasing the particle size of copper hexacyanoferrite (CuHCF). The method uses copper hexacyanoferrite (CuHCF) raw material as the working electrode, forming a three-electrode system with a counter electrode and a reference electrode. Electrochemical treatment is performed in a 0.1-8 mol / L H₂SO₄ solution. The electrochemical treatment includes alternating programs A and B, each performed 100-10000 times. In program A, the working electrode and counter electrode are connected to the positive and negative terminals of a power supply, respectively, with a current density of 0.5-10 A / g and a time of 20-400 s. In program B, the working electrode and counter electrode are connected to both ends of a load, with the current density controlled at 0.5-10 A / g and a time of 20-400 s. Specifically, in program A, electrons migrate from the counter electrode to the working electrode in the H₂SO₄ solution, and in program B, electrons migrate from the working electrode to the counter electrode in the H₂SO₄ solution. The current density can be controlled by adjusting the power supply voltage. A lower current density results in larger particle sizes for the same processing time. The more loops in programs A and B, and the longer the processing time, the larger the particle size of the product.
[0006] The small-sized CuHCF described in this invention includes, but is not limited to, CuHCF particles with irregular morphologies and sizes of ~80 nm obtained by co-precipitation. Specifically, 0.1 mol / L CuCl2 and 0.05 mol / L K3Fe(CN)6 are simultaneously added dropwise to 60 mL of deionized water and kept at 25 °C for 12 h; after centrifugation, vacuum drying for 24 h yields CuHCF material with irregular morphologies and sizes below 80 nm.
[0007] Furthermore, the CuHCF working electrode is prepared by the following method: CuHCF material, conductive agent, and binder are dissolved in a solvent and stirred for 12 hours to obtain an electrode slurry; the slurry is coated onto carbon fiber paper and vacuum dried to obtain a CuHCF electrode sheet.
[0008] In this invention, the CuHCF material, conductive agent, and binder can be any proportion that can be dissolved and coated by those skilled in the art.
[0009] The beneficial effects of this invention are as follows: This invention can controllably increase the size of CuHCF materials to a cubic morphology of 1-2 μm through a simple electrochemical method. Attached Figure Description
[0010] Figure 1 This is the XRD pattern of the CuHCF material;
[0011] Figure 2 These are SEM images of CuHCF materials.
[0012] Figure 3 These are SEM images of CuHCF materials subjected to electrochemical treatment for different times at different current densities in 0.1 mol / L H2SO4 solution.
[0013] Figure 4 These are SEM images of CuHCF materials subjected to electrochemical treatment for different times at different current densities in 0.5 mol / L H2SO4 solution.
[0014] Figure 5 These are SEM images of CuHCF materials subjected to electrochemical treatment for different times at different current densities in 1 mol / L H2SO4 solution.
[0015] Figure 6 These are SEM images of CuHCF materials subjected to electrochemical treatment for different times at different current densities in 2 mol / L H2SO4 solution.
[0016] Figure 7These are SEM images of CuHCF materials subjected to electrochemical treatment for different times at different current densities in 8 mol / L H2SO4 solution. Detailed Implementation
[0017] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.
[0018] Example 1
[0019] Step 1: CuHCF cathode material was prepared by co-precipitation. 120 mL of 0.1 mol / L copper chloride and 120 mL of 0.05 mol / L potassium ferricyanide were simultaneously added dropwise to 60 mL of deionized water. After the addition was complete, the mixture was stirred at 25°C for 24 h. The mixture was then washed clean and vacuum dried at 60°C for 12 h to obtain CuHCF material with an irregular morphology of ~80 nm.
[0020] Step 2: Dissolve CuHCF material, conductive agent Super P, and binder PVDF in N-methylpyrrolidone at a mass ratio of 7:2:1 and stir for 12 hours to obtain an electrode slurry. Coat the slurry onto a rectangular carbon paper (1×1.5cm) and vacuum dry at 60℃ for 12 hours to obtain a CuHCF electrode sheet.
[0021] Step 3: Assemble a three-electrode system using a CuHCF electrode sheet as the working electrode, a graphite rod as the counter electrode, and a saturated calomel electrode as the reference electrode in 10 mL of 0.1 mol / L H₂SO₄ solution. Process the system alternately according to program A and program B. In program A, the working electrode and counter electrode are connected to the positive and negative terminals of the power supply, respectively, with a current density of 1 A / g and a time of 200 s. In program B, the working electrode and counter electrode are connected to both ends of the load, with the current density controlled at 1 A / g and a time of 200 s.
[0022] The product obtained after repeating the A-B alternating processing procedure 100 times (total time 11.1 hours) is shown below. Figure 3 A, the product obtained after 500 repetitions (total time 55.5 hours) is shown in Figure 1. Figure 3 B, the product obtained after 1000 repetitions (total time 111.1 hours) is shown in [the original text]. Figure 3 C.
[0023] The product obtained after adjusting the current density to 0.5 A / g and repeating the process 500 times (total time 111.1 h) is shown in the figure. Figure 3 D.
[0024] The product obtained after adjusting the current density to 5 A / g and repeating the process 5000 times (total time 111.1 h) is shown in the figure. Figure 3 E.
[0025] The product obtained after adjusting the current density to 10 A / g and repeating the process 10,000 times (total time 111.1 h) is shown in the figure. Figure 3 F.
[0026] As shown in the figure, CuHCF exhibits a cubic morphology after electrochemical treatment. Furthermore, by controlling the number of charge-discharge cycles, small-sized (approximately 80 nm irregular particles) can be increased to about 2 μm, with the particle size increasing with more cycles. The particles also tend to be nested together, which helps reduce particle interfaces, prevents localized debonding and breakage of individual particles, and effectively improves its electrochemical performance.
[0027] Example 2
[0028] Step 1: CuHCF cathode material was prepared by co-precipitation. 120 mL of 0.1 mol / L copper chloride and 120 mL of 0.05 mol / L potassium ferricyanide were simultaneously added dropwise to 60 mL of deionized water. After the addition was complete, the mixture was stirred at 25°C for 24 h. The mixture was then washed clean and vacuum dried at 60°C for 12 h to obtain CuHCF material with an irregular morphology of ~80 nm.
[0029] Step 2: Dissolve CuHCF material, conductive agent Super P, and binder PVDF in N-methylpyrrolidone at a mass ratio of 7:2:1 and stir for 12 hours to obtain an electrode slurry. Coat the slurry onto a rectangular carbon paper (1×1.5cm) and vacuum dry at 60℃ for 12 hours to obtain a CuHCF electrode sheet.
[0030] Step 3: Assemble a three-electrode system using a CuHCF electrode sheet as the working electrode, a graphite rod as the counter electrode, and a saturated calomel electrode as the reference electrode in 10 mL of 0.5 mol / L H₂SO₄ solution. Process the system alternately according to program A and program B. In program A, the working electrode and counter electrode are connected to the positive and negative terminals of the power supply, respectively, with a current density of 1 A / g and a time of 200 s. In program B, the working electrode and counter electrode are connected to both ends of the load, with the current density controlled at 1 A / g and a time of 200 s.
[0031] The product obtained after repeating the A-B alternating processing procedure 100 times (total time 11.1 hours) is shown below. Figure 4 A, the product obtained after 500 repetitions (total time 55.5 hours) is shown in Figure 1. Figure 4 B, the product obtained after 1000 repetitions (total time 111.1 hours) is shown in [the original text]. Figure 4 C.
[0032] The product obtained after adjusting the current density to 0.5 A / g and repeating the process 500 times (total time 111.1 h) is shown in the figure. Figure 4 D.
[0033] The product obtained after adjusting the current density to 5 A / g and repeating the process 5000 times (total time 111.1 h) is shown in the figure. Figure 4 E.
[0034] The product obtained after adjusting the current density to 10 A / g and repeating the process 10,000 times (total time 111.1 h) is shown in the figure. Figure 4 F.
[0035] As shown in the figure, CuHCF exhibits a cubic morphology after electrochemical treatment. Furthermore, by controlling the number of charge-discharge cycles, small-sized (approximately 80 nm irregular particles) can be increased to about 2 μm, with the particle size increasing with more cycles. The particles also tend to be nested together, which helps reduce particle interfaces, prevents localized debonding and breakage of individual particles, and effectively improves its electrochemical performance.
[0036] Example 3
[0037] Step 1: CuHCF cathode material was prepared by co-precipitation. 120 mL of 0.1 mol / L copper chloride and 120 mL of 0.05 mol / L potassium ferricyanide were simultaneously added dropwise to 60 mL of deionized water. After the addition was complete, the mixture was stirred at 25°C for 24 h. The mixture was then washed clean and vacuum dried at 60°C for 12 h to obtain CuHCF material with an irregular morphology of ~80 nm.
[0038] Step 2: Dissolve CuHCF material, conductive agent Super P, and binder PVDF in N-methylpyrrolidone at a mass ratio of 7:2:1 and stir for 12 hours to obtain an electrode slurry. Coat the slurry onto a rectangular carbon paper (1×1.5cm) and vacuum dry at 60℃ for 12 hours to obtain a CuHCF electrode sheet.
[0039] Step 3: Assemble a three-electrode system using a CuHCF electrode sheet as the working electrode, a graphite rod as the counter electrode, and a saturated calomel electrode as the reference electrode in 10 mL of 1 mol / L H₂SO₄ solution. Process the system alternately according to program A and program B. In program A, the working electrode and counter electrode are connected to the positive and negative terminals of the power supply, respectively, with a current density of 1 A / g and a time of 200 s. In program B, the working electrode and counter electrode are connected to both ends of the load, with the current density controlled at 1 A / g and a time of 200 s.
[0040] The product obtained after repeating the A-B alternating processing procedure 100 times (total time 11.1 hours) is shown below. Figure 5 A, the product obtained after 500 repetitions (total time 55.5 hours) is shown in Figure 1. Figure 5 B, the product obtained after 1000 repetitions (total time 111.1 hours) is shown in [the original text]. Figure 5 C.
[0041] The product obtained after adjusting the current density to 0.5 A / g and repeating the process 500 times (total time 111.1 h) is shown in the figure. Figure 5 D.
[0042] The product obtained after adjusting the current density to 5 A / g and repeating the process 5000 times (total time 111.1 h) is shown in the figure. Figure 5 E.
[0043] The product obtained after adjusting the current density to 10 A / g and repeating the process 10,000 times (total time 111.1 h) is shown in the figure. Figure 5 F.
[0044] As shown in the figure, CuHCF exhibits a cubic morphology after electrochemical treatment. Furthermore, by controlling the number of charge-discharge cycles, small-sized (approximately 80 nm irregular particles) can be increased to about 2 μm, with the particle size increasing with more cycles. The particles also tend to be nested together, which helps reduce particle interfaces, prevents localized debonding and breakage of individual particles, and effectively improves its electrochemical performance.
[0045] Example 4
[0046] Step 1: Prepare CuHCF cathode material by co-precipitation method. Add 120 mL of 0.2...
[0047] 120 mL of copper chloride (0.05 mol / L) and potassium ferricyanide (0.05 mol / L) were simultaneously added dropwise to 60 mL of deionized water. After the addition was complete, the mixture was stirred at room temperature (25 °C) for 24 h. The mixture was then washed clean and vacuum dried at 60 °C for 12 h to obtain CuHCF material with an irregular morphology of ~80 nm.
[0048] Step 2: Dissolve CuHCF material, conductive agent Super P, and binder PVDF in N-methylpyrrolidone at a mass ratio of 7:2:1 and stir for 12 hours to obtain an electrode slurry. Coat the slurry onto a rectangular carbon paper (1×1.5cm) and vacuum dry at 60℃ for 12 hours to obtain a CuHCF electrode sheet.
[0049] Step 3: Assemble a three-electrode system using a CuHCF electrode sheet as the working electrode, a graphite rod as the counter electrode, and a saturated calomel electrode as the reference electrode in 10 mL of 2 mol / L H₂SO₄ solution. Process the system alternately according to program A and program B. In program A, the working electrode and counter electrode are connected to the positive and negative terminals of the power supply, respectively, with a current density of 1 A / g and a time of 200 s. In program B, the working electrode and counter electrode are connected to both ends of the load, with the current density controlled at 1 A / g and a time of 200 s.
[0050] The product obtained after repeating the A-B alternating processing procedure 100 times (total time 11.1 hours) is shown below. Figure 6 A, the product obtained after 500 repetitions (total time 55.5 hours) is shown in Figure 1. Figure 6 B, the product obtained after 1000 repetitions (total time 111.1 hours) is shown in [the original text]. Figure 6 C.
[0051] The product obtained after adjusting the current density to 0.5 A / g and repeating the process 500 times (total time 111.1 h) is shown in the figure. Figure 6 D.
[0052] The product obtained after adjusting the current density to 5 A / g and repeating the process 5000 times (total time 111.1 h) is shown in the figure. Figure 6 E.
[0053] The product obtained after adjusting the current density to 10 A / g and repeating the process 10,000 times (total time 111.1 h) is shown in the figure. Figure 6 F.
[0054] As shown in the figure, CuHCF exhibits a cubic morphology after electrochemical treatment. Furthermore, by controlling the number of charge-discharge cycles, small-sized (approximately 80 nm irregular particles) can be increased to about 2 μm, with the particle size increasing with more cycles. The particles also tend to be nested together, which helps reduce particle interfaces, prevents localized debonding and breakage of individual particles, and effectively improves its electrochemical performance.
[0055] Comparative Example 1
[0056] Using the CuHCF electrode sheet obtained in step 2 of Example 1 as the working electrode, a graphite rod as the counter electrode, and a saturated calomel electrode as the reference electrode, a three-electrode system was assembled in 10 mL of 8 mol / L H₂SO₄ solution. The system was processed alternately according to procedure A and procedure B. In procedure A, the working electrode and counter electrode were connected to the positive and negative terminals of the power supply, respectively, with a current density of 1 A / g and a time of 200 s. In procedure B, the working electrode and counter electrode were connected to both ends of the load, with the current density controlled at 1 A / g and a time of 200 s. The product obtained after repeating the alternating procedure A and procedure B 100 times (total time 11.1 h) is shown in the figure. Figure 7 A, the product obtained after 500 repetitions (total time 55.5 hours) is shown in Figure 1. Figure 7 B, the product obtained after 1000 repetitions (total time 111.1 hours) is shown in [the original text]. Figure 7 C. The product obtained after adjusting the current density to 0.5 A / g and repeating the process 500 times (total time 111.1 h) is shown in the figure. Figure 7 D. The product obtained after adjusting the current density to 5 A / g and repeating the process 5000 times (total time 111.1 h) is shown in the figure. Figure 7 E. The product obtained after adjusting the current density to 10 A / g and repeating the process 10,000 times (total time 111.1 h) is shown in the figure. Figure 7 F.
[0057] As can be seen from the figure, the CuHCF particles did not increase in size effectively through electrochemical treatment, and did not fully exhibit a cubic structure.
[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. A method for increasing the particle size of copper hexacyanoferrite (CuHCF), characterized in that, Using copper hexacyanoferrite (CuHCF) as the working electrode, a three-electrode system was formed with a counter electrode and a reference electrode. Electrochemical treatment was carried out in a 0.1-2 mol / L H2SO4 solution. The electrochemical treatment included alternating A and B programs, each lasting 100-10000 cycles. In program A, the working electrode and counter electrode were connected to the positive and negative terminals of a power supply, respectively, with a current density of 0.5-10 A / g and a time of 20-400 s. In program B, the working electrode and counter electrode were connected to both ends of a load, with the current density controlled at 0.5-10 A / g and a time of 20-400 s. The working electrode was prepared by dissolving CuHCF material, a conductive agent, and a binder in a solvent and stirring for 12 h to obtain an electrode slurry. The slurry was coated onto carbon fiber paper and vacuum dried to obtain the CuHCF working electrode.
2. The method for increasing CuHCF particle size according to claim 1, characterized in that, Copper hexacyanoferrite (CuHCF) raw material was prepared by coprecipitation method. 0.1 mol / L CuCl2 and 0.05 mol / L K3Fe(CN)6 were simultaneously added dropwise to 60 mL of deionized water and kept at 25℃ for 12 h. After centrifugation, the material was vacuum dried for 24 h to obtain CuHCF material with an irregular morphology of less than 80 nm in size.
3. The method according to claim 1, characterized in that, The counter electrode is a graphite rod.
4. The method according to claim 1, characterized in that, The reference electrode is a saturated calomel electrode.
Citation Information
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