Preparation method and application of ferroferric oxide / iron diselenide heterojunction electrode material
By preparing iron(III) oxide/iron(II) selenide heterojunction electrode materials, the problems of low diffusion kinetics and volume expansion in sodium-ion batteries were solved, achieving excellent cycle stability and fast charge-discharge of high-performance sodium-ion batteries, which are suitable for large-scale production.
Patent Information
- Application Number
- CN202510900523.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-01
- Publication Date
- 2025-10-28
AI Technical Summary
Existing sodium-ion batteries have low diffusion kinetics, and sodium ions tend to cause significant volume expansion when intercalating into electrode materials, making the design of high-performance sodium storage electrode materials difficult.
A method for preparing iron(III) oxide/iron(II) selenide heterojunction electrode materials is adopted. Through hydrothermal reaction and vacuum drying process, submicron spherical clusters of nanospheres and dendrite rods are formed, which increase the specific surface area and crystallinity and optimize the sodium ion diffusion path.
It achieves high cycle stability and high rate performance, improves the charge and discharge rate of sodium-ion batteries, has good reaction kinetics characteristics, and is suitable for large-scale production.
Smart Images
Figure CN120841576A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for preparing and applying a heterojunction electrode material of iron(III) oxide / iron(II) selenide, belonging to the field of inorganic material chemical preparation technology. Background Technology
[0002] Currently, the rapid development of modern science and technology and the economy heavily relies on non-renewable fossil fuels such as oil and coal. However, the excessive consumption of fossil fuels not only exacerbates resource shortages but also leads to severe environmental pollution. Developing efficient, resource-rich, and environmentally friendly new energy storage materials has become crucial for promoting the sustainable development of human society. Lithium-ion batteries, due to their advantages such as high operating voltage, lightweight design, high specific capacity, and long cycle life, have been widely used.
[0003] However, with the continued rise in demand for lithium resources, the high cost of lithium, due to its limited reserves and complex extraction processes, is increasingly becoming a bottleneck for the development of lithium-ion batteries. Sodium-ion batteries (SIBs), with their resource advantages, cost-effectiveness, and safety, are becoming an important direction for battery research and industrial application. Because sodium ions have a larger radius than lithium ions, their insertion and extraction processes in electrode materials are more difficult, resulting in significantly lower diffusion kinetics performance compared to lithium-ion batteries. Furthermore, sodium ion insertion into electrode materials is more likely to induce significant volume expansion, which places higher demands on the design and development of high-performance sodium storage electrode materials.
[0004] Given the above, developing suitable electrode materials is essential for achieving high-performance sodium-ion batteries. Iron(III) oxide / iron(II) selenide heterojunction electrode materials are considered promising anode materials for SIBs due to their excellent cycle stability and high rate performance. Summary of the Invention
[0005] This invention addresses the shortcomings of existing technologies by providing a method for preparing and applying a heterojunction electrode material of iron(II,III) oxide / iron(II,III) selenide.
[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:
[0007] This invention first discloses a method for preparing a heterojunction electrode material of iron(II,III) oxide / iron(II,III) selenide, comprising the following steps:
[0008] (1) Preparation of Fe3O4: Iron source, sodium acetate and polyethylene glycol (4000) were dissolved in 80 ml of ethylene glycol to form a homogeneous first mixed solution; the first mixed solution was transferred to a hydrothermal reactor for hydrothermal reaction. After cooling the hydrothermal reactor to room temperature, the mixture was filtered, washed and dried to obtain Fe3O4 material;
[0009] (2) Preparation of iron(III) oxide / iron(II) selenide heterojunction electrode material: The iron(III) oxide obtained in step (1) was dissolved in deionized water to obtain solution I; the selenium powder was dissolved in hydrazine hydrate to obtain solution II. Solution I and solution II were mixed and stirred thoroughly, transferred to a hydrothermal reactor for reaction, naturally cooled to room temperature, filtered and washed several times to remove impurities, and then placed in a vacuum drying oven to dry, thus obtaining the iron(III) oxide / iron(II) selenide heterojunction electrode material.
[0010] Further, the iron source in step (1) is selected from: ferric nitrate nonahydrate, ferric sulfate nonahydrate, or ferric nitrate hexahydrate.
[0011] Further, the molar ratio of iron source: sodium acetate: polyethylene glycol (4000) in step (1) is 10:1:200.
[0012] Furthermore, the hydrothermal reaction conditions described in step (1) are heating at 120-200℃ for 8-12 hours.
[0013] Furthermore, the vacuum drying temperature in step (1) is 80°C and the drying time is 12 hours.
[0014] Further, in step (2), the mass of the iron(III) oxide is 0.05-0.5g, and the volume of the deionized water is 50-100mL.
[0015] Further, the mass of the selenium powder in step (2) is 0.01g-0.5g, and the volume of hydrazine hydrate is 10-100ml.
[0016] Furthermore, the conditions for the hydrothermal reaction in step (2) are: heating at 120-200℃ for 12-24 hours.
[0017] Furthermore, the drying temperature in step (2) is 80°C and the drying time is 12 hours.
[0018] The present invention also discloses a heterojunction electrode material of iron tetroxide / iron diselenide prepared according to any of the above preparation methods.
[0019] The present invention also discloses the application of the above-mentioned iron tetroxide / iron diselenide heterojunction electrode material in the preparation of sodium-ion battery anodes.
[0020] Compared with the prior art, the advantages of the present invention are:
[0021] (1) The preparation process of this invention is simple, the yield is high, and it can be mass-produced.
[0022] (2) The iron(II) oxide / iron(II) selenide heterojunction electrode material exhibits excellent cycle stability and high rate performance, excellent electronic conductivity and sodium ion diffusion coefficient, and good reaction kinetics characteristics.
[0023] (3) The iron(III) oxide / iron(II) selenide heterojunction electrode material exhibits a unique submicron spherical cluster structure, composed of interwoven nanospheres and dendrite rods. Its highly crystalline polyhedral structure increases the specific surface area, which is beneficial for shortening the reaction time of Na+. + The diffusion path improves charge and discharge rate performance. Attached Figure Description
[0024] Figure 1 The image shows the XRD pattern of the iron(II) tetroxide / iron(II) selenide heterojunction electrode material prepared in Example 1 of this invention.
[0025] Figure 2 This is a SEM image of the iron(II) tetroxide / iron(II) selenide heterojunction electrode material prepared in Example 1 of the present invention;
[0026] Figure 3 The electrochemical performance diagram of the iron(II) tetroxide / iron(II) selenide heterojunction electrode material prepared in Example 1 of this invention is shown.
[0027] Figure 4 The image shows the XRD pattern of the iron(II) tetroxide / iron(II) selenide heterojunction electrode material prepared in Example 2 of this invention.
[0028] Figure 5 This is a SEM image of the iron(II) tetroxide / iron(II) selenide heterojunction electrode material prepared in Example 2 of the present invention;
[0029] Figure 6 The image shows the electrochemical performance of the iron(II) tetroxide / iron(II) selenide heterojunction electrode material prepared in Example 2 of this invention. Detailed Implementation
[0030] To better understand the present invention, the following description, in conjunction with embodiments and accompanying drawings, further illustrates the present invention, but the scope of the present invention is not limited to the description in the following embodiments.
[0031] Example 1
[0032] The iron(III) oxide / iron(selenide) heterojunction electrode material includes the following synthesis steps:
[0033] (1) Weigh 2.7g of ferric nitrate hexahydrate (III), 8.2g of sodium acetate and 2g of polyethylene glycol (4000) and dissolve them in ethylene glycol to form a homogeneous solution. Transfer the mixed solution to a 100mL hydrothermal reactor and carry out the hydrothermal reaction at a reaction temperature of 120℃ for 12h.
[0034] (2) After cooling the hydrothermal reactor to room temperature, the material was filtered, washed, and dried to obtain a black precipitate. The washed material was placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain iron oxide material.
[0035] (3) Dissolve 0.2g of the iron(II) oxide obtained in step (2) in 50mL of deionized water to obtain solution I;
[0036] (4) Dissolve 0.2g of selenium powder in 50mL of hydrazine hydrate to obtain solution II;
[0037] (5) Mix solution I and solution II and stir thoroughly. Transfer to a hydrothermal reactor for reaction at a temperature of 200°C for 12 hours. Cool naturally to room temperature, filter and wash repeatedly to remove impurities. Then place in a vacuum drying oven at 80°C for 12 hours to obtain the iron tetroxide / iron diselenide heterojunction electrode material.
[0038] The product obtained in this embodiment was analyzed by X-ray diffraction (see X-ray diffraction pattern). Figure 1 It was determined to be a match for ferric oxide / ferric diselenide. Scanning electron microscopy analysis results show (see...) Figure 2 The resulting product is a ball-and-stick interwoven structure.
[0039] The iron(III) oxide / iron(II) selenide heterojunction electrode material prepared in this embodiment was used to prepare the negative electrode of a sodium-ion battery. (The results were achieved at a capacity of 0.2 mAh g / g.) -1 At a current density of 503 mAh g, the material's discharge specific capacity reaches 503 mAh g. -1 (like Figure 3 It exhibits good electrochemical performance.
[0040] Example 2
[0041] The iron(III) oxide / iron(selenide) heterojunction electrode material includes the following synthesis steps:
[0042] (1) Weigh 8.1g of ferric nitrate (III) nonahydrate, 8.2g of sodium acetate and 2g of polyethylene glycol (4000) and dissolve them in ethylene glycol to form a homogeneous solution. Transfer the mixed solution to a 100mL hydrothermal reactor and carry out the hydrothermal reaction at a reaction temperature of 120℃ for 12h.
[0043] (2) After cooling the hydrothermal reactor to room temperature, the material was filtered, washed, and dried to obtain a black precipitate. The washed material was placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain iron oxide material.
[0044] (3) Dissolve 0.5g of the iron(II) oxide obtained in step (2) in 100mL of deionized water to obtain solution I;
[0045] (4) Dissolve 0.5g of selenium powder in 50mL of hydrazine hydrate to obtain solution II;
[0046] (5) Mix solution I and solution II and stir thoroughly. Transfer to a hydrothermal reactor for reaction at 180°C for 12 hours. Cool naturally to room temperature, filter and wash repeatedly to remove impurities. Then place in a vacuum drying oven at 80°C for 12 hours to obtain the iron(III) oxide / iron(II) selenide heterojunction electrode material.
[0047] The product obtained in this embodiment was analyzed by X-ray diffraction (see X-ray diffraction pattern). Figure 4 It was determined to be compatible with the ferric oxide / ferric diselenide phase. Scanning electron microscopy analysis results show (see...) Figure 5 The resulting product is hollow nanospheres.
[0048] The iron(II) tetroxide / iron(II) selenide heterojunction material prepared in this embodiment was used to prepare the negative electrode of a sodium-ion battery. (The results were achieved at a capacity of 0.2 mAh g / g.) -1 At a current density of 315 mAh g, the material's discharge specific capacity reaches 315 mAh g. -1 (like Figure 6 It exhibits good electrochemical performance.
[0049] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.
Claims
1. A method for preparing a heterojunction electrode material of iron(III) oxide / iron(II) selenide, comprising: (1) Preparation of iron oxide: Iron source, sodium acetate and polyethylene glycol are dissolved in 80 ml of ethylene glycol. The solution is mixed evenly and transferred to a hydrothermal reactor for reaction. After the reaction is completed, the hydrothermal reactor is cooled to room temperature, then filtered, washed and vacuum dried to obtain iron oxide. (2) Preparation of Fe3O4 / Fe2S heterojunction electrode material: Fe3O4 is dissolved in deionized water to obtain solution I; selenium powder is dissolved in hydrazine hydrate to obtain solution II; solution I and solution II are mixed and stirred thoroughly, transferred to a hydrothermal reactor for reaction, cooled naturally to room temperature, filtered and washed multiple times, and then placed in a vacuum drying oven to dry, thus obtaining the Fe3O4 / Fe2S heterojunction electrode material.
2. The preparation method according to claim 1, wherein: The iron source in step (1) is selected from: ferric nitrate nonahydrate, ferric sulfate nonahydrate, or ferric nitrate hexahydrate.
3. The preparation method according to claim 1, wherein: The molar ratio of iron source, sodium acetate, and polyethylene glycol (4000) in step (1) is 10:1:
200.
4. The preparation method according to claim 1, wherein: The hydrothermal reaction conditions described in step (1) are heating at 120-200℃ for 8-12 hours; The vacuum drying temperature is 80℃, and the drying time is 12 hours.
5. The preparation method according to claim 1, wherein: The mass of the iron(III) oxide in step (2) is 0.05-0.5g, and the volume of the deionized water is 50-100mL.
6. The preparation method according to claim 1, wherein: The mass of the selenium powder in step (2) is 0.01g-0.5g, and the volume of hydrazine hydrate is 10-100ml.
7. The preparation method according to claim 1, wherein: The conditions for the hydrothermal reaction in step (2) are: heating at 120-200℃ for 12-24 hours; The drying temperature is 80℃ and the drying time is 12 hours.
8. A heterojunction electrode material of iron tetroxide / iron diselenide prepared by any of the preparation methods according to claims 1 to 7.
9. The application of the iron(II) tetroxide / iron(II) selenide heterojunction electrode material according to claim 8 in the preparation of sodium-ion battery anodes.