Preparation method and application of Prussian blue material
The preparation of Prussian blue materials is accelerated through microwave reactors, which solves the problems of long reaction time and high cost in traditional methods, and realizes efficient and low-cost preparation of Prussian blue materials, improving battery performance.
Patent Information
- Application Number
- CN202510545337.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-28
- Publication Date
- 2025-08-01
AI Technical Summary
The prior art has problems such as long reaction time, high cost and high risk of toxic cyanide when preparing Prussian blue materials, and traditional methods are difficult to meet the needs of efficiently preparing battery cathode materials.
The microwave reactor and a mixed solution of chelate and cyanide source are used to accelerate the dissociation of transition metal ions and reaction with cyanide source through microwave irradiation, and Prussian blue materials are prepared to avoid a strong acid environment and long-term aging steps, and simplify the process flow.
It realizes the rapid preparation of Prussian blue materials, reduces energy consumption and cost, improves the circulation and rate performance of the materials, and adapts to the needs of different application scenarios.
Smart Images
Figure CN120398090A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of new materials, and relates to a preparation method and application of Prussian blue-based materials. Background Art
[0002] With the increasing development of technology, people's demand for energy is constantly growing. In the current energy usage distribution of society, traditional energy accounts for a large proportion, and the disadvantages of traditional energy are becoming increasingly apparent. People are urgently in need of developing clean energy. Among them, secondary energy storage batteries, as an efficient new energy storage method, have received extensive attention. Sodium-ion batteries (SIBs) have certain advantages in terms of cost, performance, and safety, and show good application prospects.
[0003] As one of the factors affecting battery performance, the selection of electrode materials largely determines the performance of SIBs. Among the cathode materials for sodium-ion batteries, Prussian blue and its analogues (PB and PBAs) have a three-dimensional open framework structure and large spatial gaps, which are beneficial to the insertion and extraction of sodium ions. PB and PBAs cathode materials also have the advantages of high theoretical capacity and low cost. Therefore, PB and PBAs cathode materials show good commercialization prospects.
[0004] Currently, the methods for preparing Prussian blue-based materials mainly include precipitation method and hydrothermal method. The precipitation method for synthesizing Prussian blue-based materials has the advantages of low cost, non-toxicity, strong controllability, and high scalability, but it requires a long reaction time and aging time. The hydrothermal method usually uses a sodium ferrocyanide (chemical formula: Na4Fe(CN)6) solution as a single iron source, and uses high temperature and strong acid conditions to slowly dissociate Fe 2+ ions, and react with the undissociated [Fe(CN)6] 4- ions, so it is easier to obtain Prussian blue-based materials with higher quality, but it also requires a long reaction time and there is a risk of generating highly toxic cyanide during the preparation process. Summary of the Invention
[0005] In view of this, the purpose of the present invention is to provide a preparation method of Prussian blue-based materials, and the second purpose is to provide an application of Prussian blue-based materials in the preparation of battery chips.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] The present invention provides a preparation method of Prussian blue-based materials, which prepares a mixed solution of a chelate and a cyanide source, puts it into a microwave reactor, and obtains the Prussian blue-based materials after the reaction ends;
[0008] Preferably, the chelate is one or more of glycine chelates, ethylenediaminetetraacetic acid chelates, citric acid chelates, gluconic acid chelates, etc.;
[0009] Preferably, the cyanide source is one or more of sodium ferrocyanide, sodium ferricyanide, potassium ferrocyanide, potassium ferricyanide, ammonium ferrocyanide;
[0010] Preferably, the microwave reaction conditions are heating to 20°C - 180°C at a rate of 1 - 10°C / min and holding for 1 - 60 min;
[0011] Preferably, the mixed solution further contains one or more of a sodium source, a reducing agent, and a surfactant;
[0012] Preferably, the sodium source is one or more of sodium chloride, sodium sulfate, and sodium acetate, the reducing agent is one or more of citric acid, ascorbic acid, ethylenediaminetetraacetic acid, and tea polyphenols, and the surfactant is one or more of polyvinylpyrrolidone and cetyltrimethylammonium bromide;
[0013] Furthermore, the application of Prussian blue - like materials in the preparation of battery positive electrode sheets;
[0014] Furthermore, the present invention also provides a battery positive electrode sheet, which is prepared by mixing Prussian blue - like materials, acetylene black, and polyvinylidene fluoride in a mass ratio of 7:2:1, adding N - methylpyrrolidone and mixing evenly, and then coating on an aluminum foil and drying in a vacuum drying oven at 80°C;
[0015] Furthermore, the present invention also provides a sodium - ion battery, which includes a battery positive electrode sheet prepared from Prussian blue - like materials, a sodium sheet as the negative electrode, an electrolyte of 1M NaClO4, EC:DEC = 1:1 vol% 5% FEC, and a separator of glass fiber separator.
[0016] The beneficial effects of the present invention are as follows:
[0017] The use of microwave irradiation to dissociate transition metal ions in the chelate and react with a cyanide source to produce Prussian blue-based materials can reduce the use of chelating agents, with a simple process flow, low cost, and short time consumption. In the present invention, microwave is used to accelerate the dissociation of transition metal ions in the chelate and promote their efficient reaction with the cyanide source, replacing traditional long-time heating or strong acid conditions. By using microwave technology in the present invention, the reaction time is shortened to 1 - 60 minutes, and no additional aging step is required. The material synthesis is completed through a one-step microwave reaction without the need for complex equipment or operation intervention. In the present invention, microwave irradiation gently dissociates metal ions in the chelate, avoiding a strong acid environment and reducing the risk of cyanide source decomposition. The energy consumption of the microwave reactor is lower than that of traditional high-temperature hydrothermal equipment, and with a short reaction time, the overall energy consumption is reduced. By adjusting the reaction parameters and additive combinations, the material properties can be directionally regulated to meet the requirements of different application scenarios. The microwave reactor supports continuous production, and the reaction conditions (temperature, time) are easy to scale up and control.
[0018] The sodium-ion half-cells assembled with the Prussian blue-based materials prepared in the present invention were tested in the voltage range of 2 - 4V. It was found that they had a capacity retention rate of 67.39% after 400 cycles at a current density of 200 mA / g, and had discharge specific capacities of 114.40, 105.42, 97.00, 86.33, and 78.92 mAh / g at current densities of 50, 100, 200, 500, and 800 mA / g, respectively. The prepared Prussian blue-based materials have good cycling performance and rate performance.
[0019] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:
[0021] Figure 1 is the X-ray diffraction pattern of the Prussian blue-based material prepared in Example 1;
[0022] Figure 2 is the rate performance graph of the Prussian blue-based material prepared in Example 1;
[0023] Figure 3 is the constant current charge-discharge curve of the Prussian blue-based material prepared in Example 1 at a current density of 200 mA / g;
[0024] Figure 4It is the galvanostatic charge-discharge curve of the Prussian blue-based material prepared in Example 2 at a current density of 50 mA / g;
[0025] Figure 5 It is the X-ray diffraction pattern of the Prussian blue-based material prepared in Example 3. Specific implementation manners
[0026] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present invention. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.
[0027] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and cannot be understood as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, and do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.
[0028] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or position relationship, it is based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.
[0029] Example 1
[0030] (1) Dissolve a certain proportion of sodium ferrocyanide and ferrous glycinate in deionized water and mix evenly.
[0031] (2) Put the evenly mixed solution into a microwave reactor and heat it to 20°C - 180°C at a rate of 10°C / min and keep it warm for 5 - 30 min to obtain the required Prussian blue-based material.
[0032] (3) Mix the Prussian blue-based material prepared in step (2) with acetylene black and polyvinylidene fluoride (PVDF) in a mass ratio of 7:2:1. Then add an appropriate amount of N-methylpyrrolidone (NMP), mix well, coat it on an aluminum foil, and dry it in a vacuum drying oven at 60 °C. Use the Prussian blue-based material as the positive electrode, a sodium sheet as the negative electrode, the electrolyte as 1M NaClO4 in EC:DEC = 1:1 vol% 5% FEC, the separator as a glass fiber separator, and assemble it into a CR2023 button cell in a glove box filled with argon and with the water and oxygen values both less than 0.1 ppm.
[0033] Example 2
[0034] (1) Dissolve a certain proportion of sodium ferrocyanide, ferrous glycinate, and copper glycinate in deionized water and mix well.
[0035] (2) Put the well-mixed solution into a microwave reactor and heat it at a rate of 10 °C / min to 20 °C - 180 °C and keep it warm for 5 - 30 min to obtain the required Prussian blue-based material.
[0036] (3) Mix the Prussian blue-based material prepared in step (2) with acetylene black and polyvinylidene fluoride (PVDF) in a mass ratio of 7:2:1. Then add an appropriate amount of N-methylpyrrolidone (NMP), mix well, coat it on an aluminum foil, and dry it in a vacuum drying oven at 60 °C. Use the Prussian blue-based material as the positive electrode, a sodium sheet as the negative electrode, the electrolyte as 1M NaClO4 in EC:DEC = 1:1 vol% 5% FEC, the separator as a glass fiber separator, and assemble it into a CR2023 button cell in a glove box filled with argon and with the water and oxygen values both less than 0.1 ppm.
[0037] Example 3
[0038] (1) Dissolve a certain proportion of sodium ferrocyanide, ferrous glycinate, and sodium chloride in deionized water and mix well.
[0039] (2) Put the well-mixed solution into a microwave reactor and heat it at a rate of 10 °C / min to 20 °C - 180 °C and keep it warm for 5 - 30 min to obtain the required Prussian blue-based material.
[0040] (3) Mix the Prussian blue-based material prepared in step (2) with acetylene black and polyvinylidene fluoride (PVDF) at a mass ratio of 7:2:1, then add an appropriate amount of N-methylpyrrolidone (NMP), mix evenly, coat it on aluminum foil, and dry it in a vacuum drying oven at 80 °C. Use the Prussian blue-based material as the positive electrode, sodium sheet as the negative electrode, the electrolyte is 1M NaClO4 in EC:DEC = 1:1 vol% 5% FEC, the separator is a glass fiber separator, and assemble it into a CR2023 button cell in a glove box filled with argon and with the water and oxygen values both less than 0.1 ppm.
[0041] Example 4
[0042] As Figure 1 shown, it is the XRD pattern of the prepared Prussian blue-based material. From Figure 1 it can be seen that the Prussian blue-based material prepared in Example 1 corresponds to the Prussian blue standard PDF card, proving that the Prussian blue-based material has been successfully synthesized. As Figure 2 shown is the rate performance of the half-cell assembled with the prepared Prussian blue-based material tested in the voltage range of 2-4V. From Figure 2 it can be seen that the Prussian blue-based material prepared in Example 1 has discharge specific capacities of 114.40, 105.42, 97.00, 86.33, 78.92 mAh / g at current densities of 50, 100, 200, 500, 800 mA / g respectively, showing good rate performance. As Figure 3 shown is the constant current charge-discharge test at a current density of 200 mA / g. It is found that after 400 cycles, there is still a capacity retention rate of 67.39%. From Figure 3 it can be seen that the Prussian blue-based material prepared in Example 1 has a capacity retention rate of 67.39% after 400 cycles at a current density of 200 mA / g.
[0043] As Figure 4 shown is the constant current charge-discharge curve of the prepared Prussian blue-based material at a current density of 50 mA / g. From Figure 4 it can be seen that the Prussian blue-based material prepared in Example 2 has a capacity retention rate of 72.75% after 50 cycles at a current density of 50 mA / g.
[0044] As Figure 5 is the XRD characterization diagram of the Prussian blue-based material prepared in Example 3. From Figure 5 it can be seen that the Prussian blue-based material prepared in Example 3 corresponds to the standard PDF card of Prussian blue, proving that Prussian blue-based material has been successfully synthesized.
[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.
Claims
1. A method for preparing Prussian blue-based materials, characterized in that: Prepare a mixed solution of a chelate and a cyanide source, place it in a microwave reactor, and obtain the Prussian blue-based material after the reaction ends.
2. The preparation method of the Prussian blue-based material according to claim 1, wherein: The chelate is one or more of glycine chelates, ethylenediaminetetraacetic acid chelates, citric acid chelates, gluconic acid chelates, etc.
3. The preparation method of the Prussian blue-based material according to claim 1, wherein: The cyanide source is one or more of sodium ferrocyanide, sodium ferricyanide, potassium ferrocyanide, potassium ferricyanide, ammonium ferrocyanide.
4. The preparation method of the Prussian blue-based material according to claim 1, characterized in that: The microwave reaction conditions are to heat to 20°C - 180°C at a rate of 1 - 10°C / min and hold for 1 - 60 min.
5. The preparation method of the Prussian blue-based material according to claim 1, characterized in that: The mixed solution further contains one or more of a sodium source, a reducing agent, and a surfactant.
6. The preparation method of the Prussian blue-based material according to claim 5, characterized in that: The sodium source is one or more of sodium chloride, sodium sulfate, sodium acetate, the reducing agent is one or more of citric acid, ascorbic acid, ethylenediaminetetraacetic acid, tea polyphenols, and the surfactant is one or more of polyvinylpyrrolidone, cetyltrimethylammonium bromide.
7. A Prussian blue-based material prepared by the method for preparing a Prussian blue-based material according to any one of claims 1 - 6.
8. Use of the Prussian blue-based material according to claim 7 in the preparation of a battery positive electrode sheet.
9. Cathode plate for battery, characterized in that: The Prussian blue-based material according to claim 7 is mixed with acetylene black and polyvinylidene fluoride in a mass ratio of 7:2:1, and then N-methylpyrrolidone is added and mixed evenly, and then coated on an aluminum foil and dried in a vacuum drying oven at 80°C to prepare.
10. Sodium ion battery, characterized in that, The battery positive electrode sheet contains the battery positive electrode sheet according to claim 9, further contains a sodium sheet as the negative electrode, the electrolyte is 1M NaClO4, EC:DEC = 1:1 vol% 5% FEC, and the separator is a glass fiber separator.