Antimony / carbon composite material and preparation method and application thereof

Abstract

The invention provides an antimony / carbon composite material and a preparation method and application thereof, and belongs to the technical field of new energy materials. The preparation method provided by the invention comprises the following steps: 1) mixing a carbon source, an antimony source and water to obtain a mixed solution; 2) heating and drying the mixed solution obtained in the step 1) to obtain a precursor; and 3) calcining the precursor obtained in the step 2) in inert gas, cooling, washing and drying to obtain the antimony / carbon composite material. The content, porosity and morphology of the carbon substrate in the composite material are further regulated and controlled by regulating and controlling the carbon source, the prepared composite material shows high specific capacity, long cycle life and excellent rate capability when being used as a lithium / sodium ion battery negative electrode, and the preparation method is simple in process, low in cost and suitable for large-scale production.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy materials, and in particular relates to an antimony / carbon composite material and a preparation method and application thereof. Background Art

[0002] Antimony (Sb), a promising high-capacity anode material, has attracted widespread attention in secondary batteries, such as lithium-ion and sodium-ion batteries. However, during charge and discharge, antimony undergoes significant volume changes, leading to electrode structure destruction and pulverization failure, affecting battery cycle stability. Furthermore, pure antimony has low electrical conductivity, limiting charge transfer efficiency. Therefore, combining antimony with carbon is an ideal solution, as it mitigates volume expansion while improving charge transfer efficiency. However, the existing antimony / carbon composite material preparation schemes still have some shortcomings: 1. The preparation process is complex and requires multi-step synthesis: some methods often require pre-synthesis of nano-antimony particles, introduction of templates (such as SiO2) to construct a porous structure, and removal of the template through an additional corrosion step. The process is cumbersome and energy-intensive; some technologies improve conductivity through nitrogen / sulfur doping, but require the introduction of additional dopants (such as melamine, thiourea) and control of reaction conditions; 2. High cost and difficulty in large-scale production: some methods use graphene oxide to load antimony particles to enhance conductivity, but the high cost of graphene and interlayer stacking problems limit its large-scale application; 3. Uneven carbon layer coating and insufficient cycle stability: The preparation process of existing antimony-carbon composite materials is complex, the carbon layer coating uniformity is poor, it is difficult to effectively alleviate volume expansion, the carbon layer has insufficient mechanical strength, and cracks still appear after long-term cycling. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a method for preparing antimony / carbon composite materials, which overcomes the shortcomings of the prior art antimony / carbon composite materials such as process defects and difficulty in meeting performance requirements. The method provided by the present invention has a simplified process, controllable structure and excellent performance.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a method for preparing an antimony / carbon composite material, comprising the following steps:

[0006] 1) mixing a carbon source, an antimony source and water to obtain a mixed solution;

[0007] 2) heating and drying the mixed solution obtained in step 1) to obtain a precursor;

[0008] 3) The precursor obtained in step 2) is calcined in an inert gas, and then cooled, washed, and dried to obtain an antimony / carbon composite material.

[0009] Preferably, the carbon source is an organic acid salt; and the antimony source is an antimony salt.

[0010] Preferably, the carbon source includes one or more of sodium citrate, sodium tartrate and sodium gluconate.

[0011] Preferably, the antimony source includes one or more of antimony chloride and antimony acetate.

[0012] Preferably, the molar ratio of the carbon source to the antimony source is 1:1 to 10:1.

[0013] Preferably, the heating temperature is 60-150° C., and the heating time is 0.5-3 h.

[0014] Preferably, the drying temperature is 50-200°C.

[0015] Preferably, the calcination temperature is 500-1000° C., the calcination time is 1-10 h, and the heating rate is 1-20° C. / min.

[0016] The present invention also provides an antimony / carbon composite material prepared by the above preparation method.

[0017] The present invention also provides an antimony / carbon composite material prepared by the above preparation method for use in lithium / sodium ion battery negative electrode materials.

[0018] The preparation method provided by the present invention achieves uniform distribution of antimony nanoparticles in a carbon matrix through the synergistic effect of a chelating agent and an antimony source and a thermal reduction process. The content, porosity, and morphology of the carbon substrate in the composite material can be regulated by regulating the carbon source. The antimony / carbon composite material prepared by the present invention exhibits high specific capacity, long cycle life, and excellent rate performance when used as the negative electrode of a lithium / sodium ion battery. The method is simple, low-cost, and suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the SEM image of Example 1;

[0020] Figure 2 is the SEM image of Example 2;

[0021] Figure 3 is the SEM image of Example 3;

[0022] Figure 4 is the SEM image of Example 4;

[0023] Figure 5 is the SEM image of Example 5;

[0024] Figure 6 are XRD patterns of Examples 1 to 5;

[0025] Figure 7 is the cycle performance diagram of Example 6;

[0026] Figure 8 This is the cycle performance diagram of Example 7. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing an antimony / carbon composite material, comprising the following steps:

[0028] 1) mixing a carbon source, an antimony source and water to obtain a mixed solution;

[0029] 2) heating and drying the mixed solution obtained in step 1) to obtain a precursor;

[0030] 3) The precursor obtained in step 2) is calcined in an inert gas, and then cooled, washed, and dried to obtain an antimony / carbon composite material.

[0031] The present invention preferably dissolves a carbon source and an antimony source in deionized water in sequence, obtains a clear solution, heats and stirs, observes the viscosity change until the fluidity is significantly reduced, transfers the solution to an oven, and dries until a fluffy precursor is obtained. The precursor is ground into powder, calcined in an inert gas atmosphere, cooled to room temperature, and the obtained black powder is washed with deionized water and ethanol and dried to obtain an antimony / carbon composite material.

[0032] The present invention has no special limitation on the sources of the carbon source and antimony source, and conventional commercial products in the field can be used.

[0033] In the present invention, the carbon source is preferably an organic acid salt, more preferably one or more of sodium citrate, sodium tartrate, and sodium gluconate.

[0034] In the present invention, the antimony source is preferably an antimony salt, more preferably one or more of antimony chloride and antimony acetate.

[0035] In the present invention, the molar ratio of the carbon source to the antimony source is preferably 1:1 to 10:1.

[0036] In the present invention, the heating temperature is preferably 60 to 150° C., more preferably 80° C.; the heating time is preferably 0.5 to 3 hours.

[0037] In the present invention, the drying is preferably oven drying, and the drying temperature is preferably 50-200°C, more preferably 150°C.

[0038] In the present invention, the inert gas preferably includes at least one of argon and nitrogen.

[0039] In the present invention, the calcination temperature is preferably 500-1000° C., more preferably 600-650° C., the calcination time is preferably 1-10 h, and the heating rate is preferably 1-20° C. / min.

[0040] The present invention also provides an antimony / carbon composite material prepared by the above preparation method.

[0041] The present invention also provides an antimony / carbon composite material prepared by the above preparation method for use in lithium / sodium ion battery negative electrode materials.

[0042] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0043] Example 1

[0044] Sodium citrate and antimony chloride were dissolved in an appropriate amount of deionized water in a ratio of 5:1 to obtain a clear solution. The solution was heated at 80°C with stirring, and the viscosity was observed until the fluidity significantly decreased. The solution was then transferred to an oven and dried at 150°C for 20 hours to obtain a fluffy precursor. The precursor was ground into a powder and heated to 650°C in an argon atmosphere at a rate of 5°C / min. The temperature was maintained for 3 hours. After cooling to room temperature in the oven, the resulting black powder was washed with deionized water and ethanol and dried.

[0045] The microscopic morphology of the antimony-carbon composite material obtained in this embodiment is: nano-sized antimony particles are coated in a honeycomb-shaped carbon substrate.

[0046] The antimony-carbon composite material can be used as a negative electrode material for secondary batteries such as lithium / sodium ion batteries, and can achieve relatively excellent performance.

[0047] Example 2

[0048] Sodium citrate and antimony chloride were dissolved in an appropriate amount of deionized water in a ratio of 3:1 to obtain a clear solution. The solution was heated at 80°C with stirring, and the viscosity was observed until the fluidity significantly decreased. The solution was then transferred to an oven and dried at 150°C for 20 hours to obtain a fluffy precursor. The precursor was ground into a powder and heated to 650°C in an argon atmosphere at a rate of 5°C / min. The temperature was maintained for 3 hours. After cooling to room temperature in the oven, the resulting black powder was washed with deionized water and ethanol and dried.

[0049] The microscopic morphology of the antimony-carbon composite material obtained in this embodiment is a porous carbon sheet loaded with antimony nanoparticles.

[0050] Example 3

[0051] Sodium gluconate and antimony chloride were dissolved in an appropriate amount of deionized water in a ratio of 4:1 to obtain a clear solution. The solution was heated at 80°C with stirring, and the viscosity was observed until the fluidity significantly decreased. The solution was then transferred to an oven and dried at 150°C for 20 hours to obtain a fluffy precursor. The precursor was ground into a powder and heated to 650°C in an argon atmosphere at a rate of 5°C / min. The temperature was maintained for 3 hours, and the resulting black powder was cooled to room temperature in the oven. The resulting black powder was then washed with deionized water and ethanol and dried.

[0052] The microscopic morphology of the antimony-carbon composite material obtained in this embodiment is nano-flake-shaped, and the thickness direction is nano-scale.

[0053] Example 4

[0054] Sodium tartrate and antimony chloride were dissolved in an appropriate amount of deionized water in a ratio of 3:1 to obtain a clear solution. The solution was heated at 80°C with stirring, and the viscosity was observed until the fluidity significantly decreased. The solution was then transferred to an oven and dried at 150°C for 20 hours to obtain a fluffy precursor. The precursor was ground into a powder and heated to 650°C in an argon atmosphere at a rate of 5°C / min. The temperature was maintained for 3 hours. After cooling to room temperature in the oven, the resulting black powder was washed with deionized water and ethanol and dried.

[0055] The microscopic morphology of the antimony-carbon composite material obtained in this embodiment is: a loofah-like carbon substrate on which antimony nanoparticles are loaded.

[0056] The antimony-carbon composite material can be used as a negative electrode material for secondary batteries such as lithium / sodium ion batteries, and can achieve relatively excellent performance.

[0057] Example 5

[0058] Sodium tartrate and antimony chloride were dissolved in an appropriate amount of deionized water in a ratio of 2:1 to obtain a clear solution. The solution was heated at 80°C with stirring, and the viscosity was observed until the fluidity significantly decreased. The solution was then transferred to an oven and dried at 150°C for 20 hours to obtain a fluffy precursor. The precursor was ground into a powder and heated to 650°C in an argon atmosphere at a rate of 5°C / min. The temperature was maintained for 3 hours. After cooling to room temperature in the oven, the resulting black powder was washed with deionized water and ethanol and dried.

[0059] The microscopic morphology of the antimony-carbon composite material obtained in this embodiment is: a micron-sized bulk carbon substrate is coated with nanometer-sized antimony particles.

[0060] Example 6

[0061] The antimony-carbon composite material obtained in Example 1 was mixed with SuperP and CMC in a ratio of 7:1:2 to form a slurry, which was then coated on copper foil as the negative electrode. The separator was Celgard 2400, the electrolyte was 1MLiPF6 in DEC:EC=1:1Vol%with5%FEC, and the lithium metal sheet was used as the positive electrode. The cells were assembled into button-type half-cells in an argon-filled glove box and the electrochemical cycling performance was tested. The results obtained in the lithium battery are shown in the attached figure. Figure 7 As shown in the figure, after 300 cycles of constant current charge and discharge at a current density of 0.1A / g, the capacity of 500.5mAh / g can still be maintained.

[0062] Example 7

[0063] The antimony-carbon composite material obtained in Example 1 was mixed with SuperP and CMC in a ratio of 7:1:2 to form a slurry, which was then coated on copper foil as the negative electrode. Glass fiber was used as the separator, and the electrolyte was 1M NaClO4 in EC:PC=1:1Vol% with 5% FEC. A sodium metal sheet was used as the positive electrode. A button-type half-cell was assembled in an argon-filled glove box to test the electrochemical cycle performance and rate performance. In the sodium battery, the results are shown in the attached figure. Figure 7 As shown in the figure, after 100 cycles of constant current charge and discharge at a current density of 0.1A / g, the capacity of 387.06mAh / g can still be maintained.

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing an antimony / carbon composite material, characterized in that: The following steps are involved: 1) mixing a carbon source, an antimony source and water to obtain a mixed solution; 2) heating and drying the mixed solution obtained in step 1) to obtain a precursor; 3) The precursor obtained in step 2) is calcined in an inert gas, and then cooled, washed, and dried to obtain an antimony / carbon composite material.

2. The method for preparing an antimony / carbon composite material according to claim 1, characterized in that: The carbon source is an organic acid salt; and the antimony source is an antimony salt.

3. The method for preparing an antimony / carbon composite material according to claim 2, characterized in that: The carbon source includes one or more of sodium citrate, sodium tartrate and sodium gluconate.

4. The method for preparing an antimony / carbon composite material according to claim 2, characterized in that: The antimony source includes one or more of antimony chloride and antimony acetate.

5. The method for preparing an antimony / carbon composite material according to claim 1, characterized in that: In the step 1), the molar ratio of the carbon source to the antimony source is 1:1 to 10:

1.

6. The method for preparing an antimony / carbon composite material according to claim 1, characterized in that: The heating temperature in step 2) is 60-150° C., and the heating time is 0.5-3 h.

7. The method for preparing an antimony / carbon composite material according to claim 1, characterized in that: The drying temperature in step 2) is 50-200°C.

8. The method for preparing an antimony / carbon composite material according to claim 1, characterized in that: In the step 3), the calcination temperature is 500-1000° C., the calcination time is 1-10 hours, and the heating rate is 1-20° C. / min.

9. The antimony / carbon composite material prepared by the method for preparing an antimony / carbon composite material according to any one of claims 1 to 8.

10. Use of the antimony / carbon composite material according to claim 9 as a negative electrode material for lithium / sodium ion batteries.

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