Sodium ion battery tin / bamboo fiber composite negative electrode material and preparation method and application thereof

Abstract

The invention relates to the technical field of sodium ion battery negative electrode materials, in particular to a sodium ion battery tin / bamboo fiber composite negative electrode material and a preparation method and application thereof. The preparation method comprises the following steps: dissolving tin salt in an organic solvent to obtain a tin salt solution; putting the bamboo fibers into a tin salt solution, dipping and drying to obtain an intermediate product; and calcining the intermediate product in a protective atmosphere to obtain the tin / bamboo fiber composite negative electrode material of the sodium-ion battery. According to the preparation method, bamboo fibers are used as a substrate material and carbonized in the calcining process to form a porous structure. The tin particles are limited in the holes, so that the problem of volume expansion generated in the circulation process can be effectively avoided, and the stability of the tin negative electrode material in the circulation process is improved. Meanwhile, the tin particles in the holes can also increase the sodium storage capacity of the negative electrode material, and the rate capability of the negative electrode material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium ion battery negative electrode materials, and in particular to a sodium ion battery tin / bamboo fiber composite negative electrode material, a preparation method thereof, and applications thereof. Background Art

[0002] Due to the abundance of raw materials and low prices, sodium ion batteries are considered to be a new generation of energy storage devices, which are expected to replace lithium ion batteries and be widely used in mobile electronic devices and large energy storage equipment. + Radius ratio Li + Due to the large volume of tin anode materials, the graphite anode material widely used in lithium-ion batteries is no longer suitable for sodium-ion batteries. Therefore, developing anode materials for sodium-ion batteries can promote their development and application. Tin anode materials have the advantages of high theoretical capacity, non-toxicity, and low cost, and hold great promise for application in sodium-ion batteries. However, tin anodes suffer from severe volume expansion during cycling, resulting in poor cycling performance. Summary of the Invention

[0003] The present invention aims to provide a tin / bamboo fiber composite negative electrode material for sodium ion batteries, and its preparation method and application, in order to address the defect of poor cycle stability caused by volume expansion when tin is used as a sodium ion negative electrode material.

[0004] To achieve the above object, the present invention provides a method for preparing a tin / bamboo fiber composite negative electrode material for a sodium ion battery, comprising the following steps:

[0005] (1) dissolving a tin salt in an organic solvent to obtain a tin salt solution;

[0006] (2) placing bamboo fiber in a tin salt solution, impregnating, and drying to obtain an intermediate product;

[0007] (3) The intermediate product is calcined under a protective atmosphere to obtain the sodium ion battery tin / bamboo fiber composite negative electrode material.

[0008] In some embodiments of the present invention, the tin salt in step (1) includes one or more of tin chloride, tin nitrate, tin carbonate, tin acetate and tin sulfate.

[0009] In some embodiments of the present invention, the organic solvent in step (1) comprises one or more of dimethyl sulfoxide, N,N-dimethylformamide, methanol, ethanol, ethanolamine and ethylenediamine.

[0010] In some embodiments of the present invention, the mass concentration of the tin salt solution in step (1) is 1%-10%.

[0011] In some embodiments of the present invention, the mass ratio of the bamboo fiber to the tin salt in step (2) is 0.1-1:0.1-1.

[0012] In some embodiments of the present invention, the immersion temperature in step (2) is 18-25° C., and the immersion time is 0.01-1 h.

[0013] In some embodiments of the present invention, the drying temperature in step (2) is 60-80° C., and the drying time is 1-12 h.

[0014] In some embodiments of the present invention, the intermediate product obtained in step (2) is a bamboo fiber-supported tin-based metal complex.

[0015] In some embodiments of the present invention, the protective atmosphere in step (3) includes nitrogen and / or argon.

[0016] In some embodiments of the present invention, the heating rate of the calcination in step (3) is 2-10° C. / min, the calcination temperature is 300-800° C., and the calcination time is 1-4 h.

[0017] The present invention also provides a sodium ion battery tin / bamboo fiber composite negative electrode material prepared by the preparation method of the sodium ion battery tin / bamboo fiber composite negative electrode material.

[0018] The present invention also provides the use of the above-mentioned sodium ion battery tin / bamboo fiber composite negative electrode material in a sodium ion battery.

[0019] The present invention has the following beneficial effects

[0020] The present invention provides a method for preparing a tin / bamboo fiber composite negative electrode material for a sodium ion battery, comprising the following steps: (1) dissolving a tin salt in an organic solvent to obtain a tin salt solution; (2) placing bamboo fiber in the tin salt solution, impregnating, and drying to obtain an intermediate product; and (3) calcining the intermediate product under a protective atmosphere to obtain the tin / bamboo fiber composite negative electrode material for a sodium ion battery. The preparation method provided by the present invention is simple and effective and is suitable for large-scale production of the tin / bamboo fiber composite negative electrode material for sodium ion batteries.

[0021] The preparation method of the present invention uses bamboo fiber as the base material, which undergoes carbonization during the calcination process, forming a porous structure. The tin particles are confined within the pores, effectively preventing volume expansion during cycling and improving the stability of the tin negative electrode material during cycling. Furthermore, the tin particles within the pores increase the negative electrode material's sodium storage capacity, enhancing its rate performance.

[0022] The preparation method of the present invention uses bamboo fiber as raw material. Bamboo, among many biomass materials, has a short growth cycle (2-3 years), low regeneration costs (annual biomass growth of 12-15%), and a wide range of sources, making it consistent with the green development strategy. Furthermore, bamboo's micro-nanoscale fiber network structure effectively buffers the volume changes of the tin negative electrode during charge and discharge. When compounded with tin materials to form a composite negative electrode material, it can significantly improve the cycling performance of the tin negative electrode.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the XRD pattern of the sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 1;

[0025] Figure 2 This is an SEM image of the sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 1;

[0026] Figure 3 This is a charge and discharge curve diagram of a sodium ion battery assembled with the sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 2;

[0027] Figure 4 This is a cycle curve diagram of a sodium ion battery assembled with the sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 2;

[0028] Figure 5 This is a rate curve of a sodium ion battery assembled with the sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 3;

[0029] Figure 6 This is a cycle curve diagram of a sodium ion battery assembled with the bamboo fiber negative electrode material prepared in Comparative Example 1;

[0030] Figure 7 This is a rate curve of a sodium ion battery assembled with the bamboo fiber negative electrode material prepared in Comparative Example 1;

[0031] Figure 8 This is a cycle curve diagram of a sodium-ion battery assembled with metallic tin negative electrode materials;

[0032] Figure 9 This is the rate curve of the sodium-ion battery assembled with metal tin negative electrode material. DETAILED DESCRIPTION

[0033] The present invention is further described below with reference to the accompanying drawings and examples. Unless otherwise defined, technical or scientific terms used herein shall have the same meanings as those commonly understood by persons of ordinary skill in the art to which the present invention pertains. The above-mentioned features or features described in the specific examples of the present invention may be combined in any manner. These specific examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention.

[0034] Example 1

[0035] This embodiment provides a method for preparing a tin / bamboo fiber composite negative electrode material for a sodium ion battery, comprising the following steps:

[0036] (1) Dissolve 1 g of tin nitrate in dimethyl sulfoxide and stir magnetically for 1 h to obtain a 3% tin salt solution;

[0037] (2) 1 g of bamboo fiber was placed in a tin salt solution, immersed at 25°C for 30 min, taken out, and dried at 60°C for 1 h to obtain an intermediate product (tin complex loaded on bamboo fiber);

[0038] (3) Under an argon atmosphere, the temperature was raised to 800°C at a heating rate of 5°C / min and calcined for 4 hours to obtain a tin / bamboo fiber composite negative electrode material for a sodium ion battery.

[0039] Example 2

[0040] This embodiment provides a method for preparing a tin / bamboo fiber composite negative electrode material for a sodium ion battery, comprising the following steps:

[0041] (1) Dissolve 0.5 g of tin chloride in N,N-dimethylformamide and stir magnetically for 12 h to obtain a tin salt solution with a mass concentration of 10%;

[0042] (2) 0.5 g of bamboo fiber was placed in a tin salt solution, immersed at 25°C for 1 hour, taken out, and dried at 80°C for 12 hours to obtain an intermediate product (tin complex loaded on bamboo fiber);

[0043] (3) Under an argon atmosphere, the temperature was raised to 600°C at a heating rate of 10°C / min and calcined for 1 hour. The intermediate product was calcined to obtain a sodium ion battery tin / bamboo fiber composite negative electrode material.

[0044] Example 3

[0045] This embodiment provides a method for preparing a tin / bamboo fiber composite negative electrode material for a sodium ion battery, comprising the following steps:

[0046] (1) Dissolve 0.1 g of tin sulfate in ethanol and stir magnetically for 2 h to obtain a tin salt solution with a mass concentration of 8%;

[0047] (2) 0.1 g of bamboo fiber was placed in a tin salt solution, immersed at 18°C ​​for 6 min, taken out, and dried at 70°C for 6 h to obtain an intermediate product (tin complex loaded on bamboo fiber);

[0048] (3) Under an argon atmosphere, the temperature was raised to 700°C at a heating rate of 2°C / min and calcined for 2 h. The intermediate product was calcined to obtain a sodium ion battery tin / bamboo fiber composite negative electrode material.

[0049] Comparative Example 1

[0050] The bamboo fiber was heated to 500°C at a heating rate of 3°C / min under a nitrogen atmosphere and calcined for 2h to obtain the bamboo fiber negative electrode material.

[0051] Characterization testing

[0052] The sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 1 was subjected to X-ray diffraction analysis, and its XRD pattern is as follows: Figure 1 As shown. Figure 1 It can be seen that Example 1 of the present invention successfully prepared a sodium ion battery tin / bamboo fiber composite negative electrode material.

[0053] The sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 1 was observed by scanning electron microscopy, and its SEM image is as follows: Figure 2 As shown. Figure 2 It can be seen that the tin particles grow evenly on the carbonized bamboo fiber skeleton.

[0054] Application Examples

[0055] The sodium ion battery tin / bamboo fiber composite negative electrode materials prepared in Examples 2 and 3 and the bamboo fiber material and metallic tin prepared in Comparative Example 1 were assembled into sodium ion batteries, and the process was as follows:

[0056] The above materials were used as negative electrodes, metallic sodium as positive electrodes, glass fiber as separators and NaClO4 as electrolytes, and were assembled into sodium ion batteries under argon atmosphere.

[0057] Performance Testing

[0058] The sodium ion battery assembled in Example 2 was subjected to the first charge and discharge test at a current density of 100 mA / g between 0.01 and 2.0 V. The charge and discharge curves are shown in FIG. Figure 3 As shown. Figure 3 It can be seen that a tin charge-discharge platform appears in the charge-discharge curve, indicating that tin participates in the deintercalation and insertion of sodium ions.

[0059] The sodium ion battery assembled in Example 2 was tested for cycle performance at a current density of 5000 mA / g. The cycle curve is shown in FIG. Figure 4 As shown. Figure 4 It can be seen that at a current density of 5000 mA / g, the sodium ion battery assembled from the sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 2 has a reversible capacity of up to 208.7 mAh / g after 2000 cycles.

[0060] The sodium ion battery assembled in Example 3 was tested for rate performance, and its rate performance curve is shown in FIG. Figure 5 As shown. Figure 5 It can be seen that the sodium ion battery assembled from the sodium ion battery tin / bamboo fiber composite negative electrode material prepared in Example 3 has excellent rate performance. At a current density of 5000 mA / g, the capacity is 295 mAh / g.

[0061] The sodium ion battery assembled in Comparative Example 1 was tested for cycle performance at a current density of 100 mA / g. Figure 6 As shown. Figure 6 It can be seen that at a current density of 100 mA / g, the reversible capacity after 50 cycles is only 45 mAh / g.

[0062] The sodium ion battery assembled in Comparative Example 1 was tested for rate performance, and its rate performance curve is shown in FIG. Figure 7 As shown. Figure 7 It can be seen that at a current density of 5000 mA / g, the reversible capacity of the battery is only 2 mAh / g.

[0063] The sodium ion battery assembled with metallic tin as the negative electrode was tested for cycle performance at a current density of 100 mA / g. Figure 8 As shown. Figure 8 It can be seen that after 50 cycles at a current density of 100 mA / g, the capacity retention rate is only 22.3%.

[0064] The sodium ion battery assembled with metallic tin as the negative electrode was tested for rate performance. Figure 9 As shown. Figure 9 It can be seen that at a current density of 5000 mA / g, the reversible capacity of the battery is only 30 mAh / g.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a tin / bamboo fiber composite negative electrode material for a sodium ion battery, characterized in that: The steps include: (1) dissolving a tin salt in an organic solvent to obtain a tin salt solution; (2) placing bamboo fiber in a tin salt solution, impregnating, and drying to obtain an intermediate product; (3) The intermediate product is calcined under a protective atmosphere to obtain the sodium ion battery tin / bamboo fiber composite negative electrode material.

2. The method for preparing the sodium ion battery tin / bamboo fiber composite negative electrode material according to claim 1, characterized in that: The tin salt in step (1) includes one or more of tin chloride, tin nitrate, tin carbonate, tin acetate and tin sulfate.

3. The method for preparing the sodium ion battery tin / bamboo fiber composite negative electrode material according to claim 1, characterized in that: The organic solvent in step (1) includes one or more of dimethyl sulfoxide, N,N-dimethylformamide, methanol, ethanol, ethanolamine and ethylenediamine.

4. The method for preparing the sodium ion battery tin / bamboo fiber composite negative electrode material according to claim 1, characterized in that: The mass concentration of the tin salt solution in step (1) is 1%-10%.

5. The method for preparing the sodium ion battery tin / bamboo fiber composite negative electrode material according to claim 1, characterized in that: The mass ratio of the bamboo fiber to the tin salt in step (2) is 0.1-1:0.1-1.

6. The method for preparing the sodium ion battery tin / bamboo fiber composite negative electrode material according to claim 1, characterized in that: The immersion temperature in step (2) is 18-25° C., and the immersion time is 0.01-1 h.

7. The method for preparing the sodium ion battery tin / bamboo fiber composite negative electrode material according to claim 1, characterized in that: The protective atmosphere in step (3) includes nitrogen and / or argon.

8. The method for preparing the sodium ion battery tin / bamboo fiber composite negative electrode material according to claim 1, characterized in that: The heating rate of the calcination in step (3) is 2-10°C / min, the calcination temperature is 300-800°C, and the calcination time is 1-4h.

9. A sodium ion battery tin / bamboo fiber composite negative electrode material prepared by the method for preparing a sodium ion battery tin / bamboo fiber composite negative electrode material according to any one of claims 1 to 8.

10. Use of the sodium ion battery tin / bamboo fiber composite negative electrode material according to claim 9 in a sodium ion battery.

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