Preparation of iron antimonate / diantimonium tetroxide / rGO composite and application thereof in lithium / sodium ion battery

Abstract

The application provides a preparation method of a ferrous antimonate / diantimonium tetroxide / rGO composite material, uses +3 valence antimony as raw material, forms +5 valence antimony ions in a solvent thermal treatment, makes the +5 valence antimony ions form FeSbO4 / Sb2O4 heterojunction nanoparticles on the surface of reduced graphene oxide (rGO) sheets in situ by the action of +3 valence iron ions, and finally obtains the FeSbO4 / Sb2O4 / rGO composite material. The composite material can be used as a lithium / sodium ion battery negative electrode material, the unique FeSbO4 / Sb2O4 heterojunction nanoparticles and the excellent mechanical stability of rGO effectively alleviate the volume effect of the composite material in the cycle process, improve the conductivity of the electrode, and make the composite material have excellent electrochemical lithium / sodium storage performance.

Description

Technical Field

[0001] This invention belongs to the fields of composite materials and lithium / sodium-ion battery technology, specifically relating to a method for preparing a high-performance FeSbO4 / Sb2O4 / rGO composite material, which is mainly used as a negative electrode material for lithium / sodium-ion batteries. Background Technology

[0002] Currently, lithium-ion batteries (LIBs) have become the most widely used power source for portable electronic devices, electric vehicles, and grid energy storage applications due to their high operating voltage (3.0-3.8 V), long cycle life, and low self-discharge rate. As an alternative rechargeable battery, sodium-ion batteries (SIBs) show great promise for large-scale energy storage applications due to the abundant sodium resources in the Earth's crust. With the increasing demand for renewable energy, high-energy-density renewable lithium / sodium-ion batteries have enormous application potential in large-scale energy storage systems, while also placing higher demands on their performance. Therefore, there is an urgent need to find next-generation electrode materials with high theoretical capacity. Among anode materials, antimony oxide has become a promising anode material for lithium / sodium-ion batteries due to its high theoretical capacity and suitable lithium / sodium storage potential. However, the huge volume expansion during the electrochemical reaction and the high energy barrier in the reversible process of antimony oxide anode materials severely limit their widespread application.

[0003] In recent years, to address the aforementioned issues, a relatively effective strategy has been to nanoscale antimony oxide or combine it with materials with good conductivity to create binary or multi-component composite materials. For example, combining it with conductive carbon materials or transition metals can compensate for the poor conductivity of antimony oxide itself. Nanoscale fabrication is typically achieved by adding surfactants or dispersants, or by adjusting the pH value. Meanwhile, graphene oxide (GO), a planar two-dimensional material composed of carbon atoms arranged in a hexagonal honeycomb lattice with sp2 hybrid orbitals, exhibits good conductivity and flexibility, and has been proven to be an ideal carrier material.

[0004] FeSbO4 can also be used as a negative electrode material for lithium / sodium-ion batteries, but its preparation process is mostly solid-state high-temperature oxidation sintering, resulting in relatively low lithium / sodium storage capacity. For example, the literature (Electrochemically induced amorphization and unique lithium and sodium storage pathways in FeSbO4 nanocrystals, ACS ApplMater Interfaces, 2019, 11, 22, 20082-20090) discloses a method for preparing FeSbO4 composite materials by high-temperature calcination. This process uses ferric acetate and antimony acetate as raw materials, polyvinylpyrrolidone as a size regulator, and water as a solvent. After mixing, the mixture is calcined at a high temperature (1000℃) under air conditions to prepare pure FeSbO4 nanocrystalline materials; however, its capacity is relatively low when used as a lithium / sodium storage negative electrode (the specific capacity is stable at 600 mAh / g for lithium storage and approximately 150-250 mAh / g for sodium storage). Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing high-performance FeSbO4 / Sb2O4 / rGO composite materials.

[0006] Another object of the present invention is to provide the application of FeSbO4 / Sb2O4 / rGO composite material in lithium / sodium ion batteries.

[0007] I. Preparation of FeSbO4 / Sb2O4 / rGO composite materials

[0008] This invention discloses a method for preparing a high-performance FeSbO4 / Sb2O4 / rGO composite material. Antimony trioxide is used as the antimony source. It is ultrasonically dispersed and dissolved in an alcohol solution to obtain a transparent alkoxide solution A. Sodium alginate and iron salt are dissolved in deionized water to obtain solution B. Solutions A and B are stirred and ultrasonically mixed until homogeneous. Then, an aqueous solution of graphene oxide (GO) is added, and the mixture is continuously stirred until homogeneous, yielding an alcohol / water mixed solution of +3 valent antimony, +3 valent iron, and graphene oxide. The mixed solution is subjected to a closed solvothermal treatment in a high-pressure reactor. After cooling to room temperature, it is washed with deionized water and ethanol, and dried to obtain the FeSbO4 / Sb2O4 / rGO composite material. The iron salt is a +3 valent iron salt, including but not limited to ferric chloride, ferric nitrate, and ferric sulfate. The alcohol is ethanol, ethylene glycol, or glycerol. In the alcohol / water mixed solution of +3 valent antimony, +3 valent iron, and graphene oxide, the molar ratio of antimony to iron is 10:1 to 1:10, and the molar ratio of antimony to graphene oxide (based on carbon) is 1:5 to 1:15; the volume ratio of alcohol to water in the alcohol / water mixed solution is 3:1 to 1:3. The solvothermal treatment temperature is 100 to 150°C, and the holding time is 4 to 24 hours. This preparation method does not require the addition of dispersants or size regulators, nor does it require high-temperature (>500°C) oxidation treatment to prepare FeSbO4 / Sb2O4 / rGO nanocomposite materials.

[0009] Annealing the FeSbO4 / Sb2O4 / rGO composite material at a low temperature for 1-4 hours under inert gas protection can further improve the reduction degree of reduced graphene oxide, obtaining the annealed composite material FeSbO4 / Sb2O4 / rGO-T. The low-temperature annealing temperature is 200℃-300℃. The inert gas includes nitrogen or argon.

[0010] The formation mechanism of the FeSbO4 / Sb2O4 / rGO nanocomposite is as follows: Antimony trivalent (+3) is oxidized by graphene oxide during solvothermal treatment to form antimony pentavalent (+5), and then FeSbO4 phase is formed in situ under the action of ferric ions (+3). During the reaction, graphene oxide (GO) is reduced and acts as an oxidant to partially oxidize Sb. 3+ Oxidation to Sb 5+ Thus, Sb₂O₄ is obtained; while Fe 3+ Its existence is due to its relationship with Sb 5+ Partial Sb production that promotes GO oxidation through strong interactions 5+ The FeSbO4 phase is formed instead of the Sb2O4 phase; at the same time, due to Sb 5+ The oxidation formation occurs on the surface of graphene oxide; FeSbO4 is generated in situ on the surface of reduced graphene oxide, effectively suppressing the simultaneous formation of Sb. 3+ and Sb 5+The coarsening process of Sb₂O₄ particles, i.e., the formation of FeSbO₄, simultaneously refines the particle size of Sb₂O₄ and uniformly anchors these nanoparticles on rGO nanosheets. Furthermore, the strong interaction between FeSbO₄, Sb₂O₄, and rGO due to their in-situ formation during the reaction effectively improves and enhances the structural stability of the composite material and the charge / sodium ion migration during the electrochemical reaction. Combined with the excellent mechanical stability of rGO, the volume effect of the active components FeSbO₄ and Sb₂O₄ during cycling is effectively mitigated. Simultaneously, the built-in electric field of this nanostructure accelerates electron-ion transfer, improving the charge transfer kinetics of the material. The synergistic effect among FeSbO₄, Sb₂O₄, and rGO can alleviate the volume expansion problem of antimony oxide during cycling and improve the electrochemical performance of the electrode material.

[0011] This invention prepares a composite material of FeSbO4, Sb2O4, and rGO. Current technologies struggle to obtain such composites with unique structures and interactions. In previous research, the applicant discovered that typically only composites of Fe2O3, Sb2O3, or Sb2O4 and rGO can be obtained, and the formation of the FeSbO4 phase is difficult without the addition of size modifiers such as surfactants and dispersants. This invention addresses the issue that while FeSbO4 exhibits superior conductivity and cycle stability, its reversible capacity is relatively low; and while Sb2O4 has a high theoretical lithium / sodium storage capacity, its large volume change and poor conductivity lead to poor cycle stability. By designing a suitable method, this invention prepares a composite material of FeSbO4, Sb2O4, and rGO, and utilizes their respective advantages and synergistic effects to obtain a high-performance lithium / sodium storage anode material, which has significant practical application value and importance.

[0012] II. Structural Characterization of FeSbO4 / Sb2O4 / rGO Composite Material

[0013] The structure of the FeSbO4 / Sb2O4 / rGO composite material prepared in this invention is characterized below by X-ray diffraction (XRD) and scanning electron microscopy (SEM).

[0014] Figure 1 The image shows the X-ray diffraction (XRD) pattern of the FeSbO4 / Sb2O4 / rGO composite material prepared in this invention. Figure 1It can be seen that the diffraction peaks of the FeSbO4 / Sb2O4 / rGO composite materials prepared in Examples 1 and 2 are in complete agreement with the diffraction peaks of the FeSbO4 phase (standard card JCPDS NO.34-0372) and the Sb2O4 phase (standard card JCPDS NO.11-0694), indicating that the FeSbO4 / Sb2O4 / rGO composite materials were successfully synthesized. It can be seen from the figure that the phase composition of the composite materials prepared at different temperatures did not change, and they were all FeSbO4 and Sb2O4.

[0015] Figure 2 Scanning electron microscope (SEM) image of the FeSbO4 / Sb2O4 / rGO composite material prepared in this invention. Figure 2 The morphology of the FeSbO4 / Sb2O4 / rGO composite materials prepared in Examples 1 and 2 can be seen. As can be seen from the two figures, with the increase of solvothermal temperature, the number of particles on the surface of reduced graphene oxide is significantly reduced, and the particle size is small and the distribution is relatively uniform.

[0016] Figure 3 The image shows the X-ray diffraction (XRD) pattern of the FeSbO4 / Sb2O4 / rGO-T composite material prepared in this invention. Figure 3 It can be seen that the structural composition of the composite material changes as the annealing temperature increases.

[0017] Figure 4 This is a scanning electron microscope (SEM) image of the FeSbO4 / Sb2O4 / rGO-T composite material prepared in this invention. Figure 4 It can be seen that as the annealing temperature increases, the structural composition of the composite material changes, with the formation of Sb2O3 and the particle size of the material gradually increasing.

[0018] III. Performance Testing of FeSbO4 / Sb2O4 / rGO Composite Material as a Negative Electrode Material for Lithium / Sodium-ion Batteries

[0019] Test method: A certain amount of FeSbO4 / Sb2O4 / rGO and FeSbO4 / Sb2O4 / rGO-T composite materials were ground and mixed with polyvinylidene fluoride and acetylene black to prepare slurries, and then assembled into coin cells. The cycle performance of the cells was tested using the Blue Electric Test System.

[0020] Figure 5 The cycling performance diagram of the FeSbO4 / Sb2O4 / rGO composite material prepared according to this invention as a negative electrode material for lithium-ion batteries. From... Figure 5 The results show that the FeSbO4 / Sb2O4 / rGO composite materials prepared in Examples 1 and 2, when used as a negative electrode material for lithium-ion batteries, exhibit performance at 200 mA g. -1At current densities of 811.14 mAh g, respectively -1 1079.4 mAh g -1 The initial reversible specific capacity and initial coulombic efficiency were 53.44% and 56.96%, respectively. After 200 cycles, the reversible specific capacity remained at 657.9 mAh g⁻¹. -1 966.7 mAh g -1 This demonstrates that the FeSbO4 / Sb2O4 / rGO composite material prepared in this invention has excellent cycle stability.

[0021] Figure 6 The cycling performance of the FeSbO4 / Sb2O4 / rGO-T composite material prepared in this invention as a negative electrode material for lithium-ion batteries is shown in the figure. Figure 6 The results show that the FeSbO4 / Sb2O4 / rGO-T composite materials prepared in Examples 3 and 4, when used as a negative electrode material for lithium-ion batteries, exhibit performance at 200 mA g. -1 At current densities of 1019.3 mAh g, respectively -1 833.3 mAhg -1 The initial reversible specific capacity and initial coulombic efficiency were 64.69% and 68.85%, respectively. After 200 cycles, the reversible specific capacity remained at 999 mAh g⁻¹. -1 430.5 mAh g -1 This demonstrates that the FeSbO4 / Sb2O4 / rGO-T composite material prepared in this invention has excellent cycle stability.

[0022] Figure 7 Cycle performance diagrams of the FeSbO4 / Sb2O4 / rGO and FeSbO4 / Sb2O4 / rGO-T composite materials prepared for this invention as anode materials in sodium-ion batteries. From... Figure 7 The results show that the FeSbO4 / Sb2O4 / rGO and FeSbO4 / Sb2O4 / rGO-T composite materials prepared in Examples 2 and 3, when used as anode materials for sodium-ion batteries, exhibit performance at 200 mA g. -1 At current densities of 391.55 mAh g, respectively -1 449.8 mAh g -1 The initial reversible specific capacity and initial coulombic efficiency were 40% and 40.66%, respectively. After 200 cycles, the reversible specific capacity remained at 349.3 mAh g⁻¹. -1 366.5 mAh g -1 This demonstrates that the FeSbO4 / Sb2O4 / rGO and FeSbO4 / Sb2O4 / rGO-T composite materials prepared in this invention have excellent cycle stability.

[0023] In summary, this invention first prepares FeSbO4 / Sb2O4 / rGO composite materials using antimony trioxide, graphene oxide, iron salts, and sodium alginate as raw materials via a one-step solvothermal method, and then prepares FeSbO4 / Sb2O4 / rGO-T composite materials by combining low-temperature annealing treatment. This invention employs a solvothermal method to prepare FeSbO4 / Sb2O4 / rGO composite materials. In this method, +3 valent antimony raw materials are oxidized to +5 valent antimony ions during solvothermal treatment with graphene oxide. Under the action of +3 valent iron ions, FeSbO4 / Sb2O4 heterojunction nanoparticles are formed in situ on the surface of reduced graphene oxide (rGO) sheets, uniformly anchored on the rGO, ultimately obtaining the FeSbO4 / Sb2O4 / rGO composite material. Both the composite material and its annealed product can be used as anode materials for lithium / sodium-ion batteries. The unique FeSbO4 / Sb2O4 heterojunction nanoparticles and the excellent mechanical stability of rGO effectively alleviate the volume effect of the composite material during cycling and improve the conductivity of the electrode, giving the composite material excellent electrochemical lithium / sodium storage performance. Attached Figure Description

[0024] Figure 1 X-ray diffraction (XRD) patterns of FeSbO4 / Sb2O4 / rGO composite materials prepared under different embodiments of the present invention.

[0025] Figure 2 These are scanning electron microscope (SEM) images of the FeSbO4 / Sb2O4 / rGO composite materials prepared in different embodiments of the present invention.

[0026] Figure 3 X-ray diffraction (XRD) patterns of FeSbO4 / Sb2O4 / rGO-T composite materials prepared under different embodiments of the present invention.

[0027] Figure 4 These are scanning electron microscope (SEM) images of the FeSbO4 / Sb2O4 / rGO-T composite materials prepared under different embodiments of the present invention.

[0028] Figure 5 The graphs show the cycle performance of the FeSbO4 / Sb2O4 / rGO composite material prepared in different embodiments of the present invention when used as the negative electrode of a lithium-ion battery.

[0029] Figure 6 The graphs show the cycle performance of the FeSbO4 / Sb2O4 / rGO-T composite materials prepared in different embodiments of the present invention when used as the negative electrode of a lithium-ion battery.

[0030] Figure 7The graphs show the cycle performance of FeSbO4 / Sb2O4 / rGO and FeSbO4 / Sb2O4 / rGO-T composite materials prepared under different embodiments of the present invention when used as anodes in sodium-ion batteries. Detailed Implementation

[0031] The preparation and properties of the FeSbO4 / Sb2O4 / rGO composite material of the present invention will be further illustrated below through specific embodiments.

[0032] Example 1

[0033] (1) First, 0.3 g of antimony trioxide was ultrasonically dispersed and dissolved in 30 mL of ethylene glycol solution to obtain transparent alkoxide solution A. 0.1 g of sodium alginate and 0.2 g of FeCl3·6H2O were dissolved in 10 mL of deionized water to obtain solution B. Solutions A and B were stirred and ultrasonically mixed evenly. Then, 20 mL of GO aqueous solution was added and the mixture was stirred until homogeneous. The mixture was then subjected to solvent heat treatment in a high-pressure reactor at a constant temperature of 120℃ for 12 h. After cooling to room temperature, it was washed with deionized water and ethanol and dried to obtain FeSbO4 / Sb2O4 / rGO composite material.

[0034] When this composite material is used as a negative electrode material for lithium-ion batteries, at 200 mA g... -1 It has a current density of 811.14 mAh g. -1 The initial reversible specific capacity was 53.44%, with an initial coulombic efficiency of 53.44%. After 50 cycles, the reversible specific capacity remained at 634.5 mAh g⁻¹. -1 It exhibits excellent cycle stability.

[0035] Example 2

[0036] (1) First, 0.3 g of antimony trioxide was ultrasonically dispersed and dissolved in 30 mL of ethanol solution to obtain transparent alkoxide solution A. 0.1 g of sodium alginate and 0.3 g of FeCl3·6H2O were dissolved in 10 mL of deionized water to obtain solution B. Solutions A and B were stirred and ultrasonically mixed evenly. Then, 20 mL of GO aqueous solution was added and the mixture was stirred until uniform. The mixture was then subjected to solvent heat treatment in a high-pressure reactor at a constant temperature of 140℃ for 12 h. After cooling to room temperature, it was washed with deionized water and ethanol and dried to obtain FeSbO4 / Sb2O4 / rGO composite material.

[0037] When this composite material is used as a negative electrode material for lithium-ion batteries, at 200 mA g... -1 It has a current density of 1079.4 mAh g. -1The initial reversible specific capacity was 56.96% with an initial coulombic efficiency. After 50 cycles, the reversible specific capacity remained at 945.9 mAh g⁻¹. -1 It exhibits excellent cycle stability; when used as a sodium-ion battery anode material, it maintains good performance at 200 mA g⁻¹. -1 It has a current density of 391.55 mAh g⁻¹ -1 The initial reversible specific capacity was 40% with an initial coulombic efficiency. After 50 cycles, the reversible specific capacity remained at 446.4 mAh g⁻¹. -1 It exhibits excellent cycle stability.

[0038] Example 3

[0039] (1) First, 0.3 g of antimony trioxide was ultrasonically dispersed and dissolved in 30 mL of glycerol solution to obtain transparent alkoxide solution A. 0.1 g of sodium alginate and 0.2 g of FeCl3·6H2O were dissolved in 10 mL of deionized water to obtain solution B. Solutions A and B were stirred and ultrasonically mixed evenly. Then, 20 mL of GO aqueous solution was added and the mixture was stirred until homogeneous. The mixture was then subjected to solvent heat treatment in a high-pressure reactor at a constant temperature of 140℃ for 12 h. After cooling to room temperature, it was washed with deionized water and ethanol and dried to obtain FeSbO4 / Sb2O4 / rGO composite material.

[0040] (2) The FeSbO4 / Sb2O4 / rGO composite material was annealed at 200℃ for 3 h under inert gas protection to obtain the FeSbO4 / Sb2O4 / rGO-T composite material.

[0041] When this composite material is used as a negative electrode material for lithium-ion batteries, at 200 mA g... -1 It has a current density of 1019.3 mAh g. -1 The initial reversible specific capacity was 64.69%, with an initial coulombic efficiency of 64.69%. After 50 cycles, the reversible specific capacity remained at 1042.7 mAh g⁻¹. -1 It exhibits excellent cycle stability; when used as a sodium-ion battery anode material, it maintains good performance at 200 mA g⁻¹. -1 After 50 cycles at a current density, the reversible capacity remains at 459.5 mA g. -1 .

[0042] Example 4

[0043] (1) First, 0.3 g of antimony trioxide was ultrasonically dispersed and dissolved in 30 mL of ethylene glycol solution to obtain transparent alkoxide solution A. 0.1 g of sodium alginate and 0.5 g of FeCl3·6H2O were dissolved in 10 mL of deionized water to obtain solution B. Solutions A and B were stirred and ultrasonically mixed evenly. Then, 20 mL of GO aqueous solution was added and the mixture was stirred until uniform. The mixture was then subjected to solvent heat treatment in a high-pressure reactor at a constant temperature of 140℃ for 12 h. After cooling to room temperature, it was washed with deionized water and ethanol and dried to obtain FeSbO4 / Sb2O4 / rGO composite material.

[0044] (2) The FeSbO4 / Sb2O4 / rGO composite material was annealed at 250℃ for 3 h under inert gas protection to obtain the FeSbO4 / Sb2O4 / rGO-T composite material.

[0045] When this composite material is used as a negative electrode material for lithium-ion batteries, at 200 mA g... -1 It has a current density of 833.3 mAh g. -1 The initial reversible specific capacity was 68.85% with an initial coulombic efficiency. After 200 cycles, the reversible specific capacity remained at 536.2 mAh g⁻¹. -1 .

Claims

1. A method for preparing a ferric antimonate / diantimonium tetroxide / rGO composite material, characterized by comprising the following steps: Sb2O4 / rGO composite material is obtained by the following steps: dispersing and dissolving antimony trioxide in an alcohol solution to obtain a transparent alcohol salt solution A, dissolving sodium alginate and iron salt in deionized water to obtain solution B, stirring and ultrasonically mixing solution A and solution B uniformly, then adding a graphene oxide aqueous solution, continuously stirring the mixed solution until it is uniform, obtaining an alcohol / water mixed solution of +3 valence antimony, +3 valence iron and graphene oxide, carrying out a closed solvothermal treatment on the mixed solution at 100-150℃ for 4-24 hours, washing with deionized water and ethanol after cooling to room temperature, and drying to obtain the FeSbO4 / Sb2O4 / rGO composite material. In the alcohol / water mixed solution of +3 valence antimony, +3 valence iron and graphene oxide, the molar ratio of antimony to iron is 10:1-1:5, and the molar ratio of graphene oxide to antimony, calculated based on carbon elements, is 5:1-15:

1. ​ 2. The preparation method of the iron antimony / antimony tetroxide / rGO composite material as described in claim 1, characterized in that: The FeSbO4 / Sb2O4 / rGO composite material is annealed at low temperature under inert gas protection for 1-4 hours to obtain the annealed composite material FeSbO4 / Sb2O4 / rGO-T, and the low temperature annealing treatment temperature is 200-300℃.

3. The preparation method of the iron antimonate / antimony tetroxide / rGO composite material as described in claim 1, characterized in that: The iron salt is a +3 valence iron salt, which is ferric chloride, ferric nitrate or ferric sulfate.

4. The preparation method of the iron antimony / antimony tetroxide / rGO composite material as described in claim 1, characterized in that: The alcohol is ethanol, ethylene glycol or glycerol.

5. The preparation method of the iron antimonate / antimony tetroxide / rGO composite material as described in claim 1, characterized in that: In the alcohol / water mixed solution, the volume ratio of alcohol to water is 3:1-1:

3.

6. Application of the FeSbO4 / Sb2O4 / rGO composite material prepared by the method of claim 1 in lithium / sodium ion battery negative electrode materials.

7. Application of the FeSbO4 / Sb2O4 / rGO-T composite material prepared by the method of claim 2 in lithium / sodium ion battery negative electrode materials.

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