A two-dimensional SbBi alloy material and a preparation method and application thereof

Abstract

The application belongs to the field of energy storage material preparation, and discloses a two-dimensional SbBi alloy material, a preparation method and application thereof.The preparation method comprises the following operation steps: adding hydrochloric acid into ethylene glycol, uniformly dispersing, then adding SbCl3 and BiCl3, and ultrasonic stirring until completely dissolved; adding iron powder, adding hydrochloric acid to remove residual iron powder after the reaction is completed; finally, using ethanol and water for filtration, and freeze-drying to obtain the two-dimensional SbBi alloy material.The application adopts a one-step co-substitution method to accurately proportionally prepare two-dimensional SbBi alloy materials at normal temperature, and the obtained materials have excellent potassium storage performance without being combined with any material.

Description

Technical Field

[0001] This invention belongs to the field of energy storage material preparation, and specifically relates to a two-dimensional SbBi alloy material, its preparation method and application. Background Technology

[0002] Since the commercialization of lithium-ion batteries (LIBs), they have dominated the portable electronic device and electric vehicle markets due to their lightweight characteristics. On the one hand, developing high-capacity lithium-ion batteries is an urgent problem to solve; on the other hand, since lithium reserves cannot meet the ever-increasing demand, replacing lithium-ion batteries with new energy storage devices in the field of low-cost, large-scale energy storage is also particularly urgent. Therefore, potassium-ion batteries (PIBs), which are similar in principle to LIBs, have attracted increasing attention due to their relatively high volumetric and gravimetric energy density, especially the abundant reserves of potassium. However, the large radius of potassium ions (K+)... This leads to slow electrochemical kinetics and large volume changes during potassium insertion and removal processes. Given these challenges, various materials (e.g., carbonaceous materials, metal sulfides, oxides, and phosphides) have been explored as suitable anodes for PIBs, with alloy-based electrode materials more readily achieving high-capacity storage through alloying reaction mechanisms. Furthermore, combining the advantages of different metals can mitigate the shortcomings of single-metal alloying for potassium storage through the synergistic effect of multi-component alloy formulations.

[0003] Bismuth (Bi) metal is considered a promising candidate for alloy anodes due to its high conductivity (77.5 x 10⁻⁶). 4 Sm -1 Bi has advantages in terms of low potential hysteresis and inherent physicochemical properties. Generally, Bi is very advantageous. However, its low specific capacity (384 mAh g⁻¹) is a drawback. -1 The high specific capacity of Bi has severely limited its further development in PIBs. Inspired by the advantages and disadvantages of various alloy-based electrode materials, combining Bi with a metal possessing high specific capacity may be an effective strategy to improve performance. In the case of alloying, antimony (Sb) from the same group is usually chosen as the first choice for alloying. On the one hand, it has a layered structure similar to Bi, and on the other hand, metallic Sb alone can provide a theoretical capacity of 660 mAh g⁻¹, and has a higher conductivity than Bi (240 × 10⁻¹). 4The K3(Bi,Sb) alloy is formed during the complete potassium-modification process, which significantly exceeds the theoretical capacity of other alloy-based anodes besides phosphorus and exhibits excellent potassium-ion storage performance. Furthermore, due to the structural similarity between Sb and Bi, they can synergistically interact, allowing for mixing in any molar ratio to construct a series of SbBi alloy materials with varying proportions. Additionally, the 384% volume expansion of K3(Bi,Sb) is much smaller than that of K3Bi (406%) and K3Sb (407%), which is beneficial for enhancing the overall electrode's structural integrity.

[0004] As is well known, 2D nanomaterials not only exhibit a large specific surface area to volume ratio, which is highly beneficial for electrolyte wetting, but also often demonstrate good mechanical flexibility, thus providing excellent structural stability during the cycling process of electrochemical reactions. 2D Bi anodes exhibit excellent long-term stability in PIBs, but their low theoretical capacity hinders their practical application. Therefore, it is crucial to design and fabricate a two-dimensional alloy material with a higher theoretical capacity in a simple one-step process for use in energy storage materials. Although SbBi alloy anodes have been widely reported in PIBs, most studies rely on composites with carbon, graphene, etc., to provide relatively outstanding stability. However, reports on the one-step synthesis of a series of two-dimensional SbBi alloy structures are rare. Therefore, research on developing a two-dimensional SbBi alloy with arbitrary proportions for simultaneous application in both PIBs and LIBs is extremely challenging.

[0005] A conventional method to mitigate volume expansion and improve cycle stability of antimony-bismuth alloys is to composite them with conductive carbon. However, this method is complex and yields poor capacity performance. For example, Chinese patent (CN202210485581.7) prepared a nitrogen-doped antimony-bismuth alloy composite material for sodium-ion batteries. At a current density of 0.1C, the initial discharge capacity of the obtained negative electrode material was 620.41 mAh / g, but after 50 charge-discharge cycles, the discharge capacity was only 407.91 mAh / g, with a capacity retention rate of only 65.75%. Besides composites with carbon materials, combining antimony-based materials with other elements in binary alloys is another method to improve their stability. The introduction of a second metal can act as a buffer layer, reducing volume changes during electrode cycling. For example, Chinese patent (application number: CN202211219479.9) introduces a rice-ear-like nanowall array structure with a uniform heterogeneous interface distribution grown on a copper substrate. During electrodeposition, Bi, Sb, and Se are simultaneously incorporated into the nanowalls, forming an array structure with uniformly dispersed SbBi alloy, metal selenide Bi2Se3, and Sb2Se3 phases. This ensures that the heterogeneous interfaces between different phases are also uniformly distributed throughout the entire structure, facilitating Na+ diffusion and promoting electron conduction, thereby improving the rate performance of the material. However, this method is complex and requires a short number of cycles. Currently, other proposed solutions are not pure two-dimensional SbBi alloys and have not been applied in potassium-ion batteries. Summary of the Invention

[0006] In order to overcome the shortcomings and deficiencies of existing SbBi alloys, such as poor electrochemical performance and poor cycle performance due to large volume expansion, the primary objective of this invention is to provide a method for preparing two-dimensional SbBi alloy (2D-SbxBiy alloy) materials.

[0007] Another objective of this invention is to provide a two-dimensional SbBi alloy material prepared by the above-described preparation method, which has superior performance compared to other doped SbBi alloy materials.

[0008] Another object of the present invention is to provide an application of the above-mentioned two-dimensional SbBi alloy material.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] A method for preparing a two-dimensional SbBi alloy material, comprising the following steps:

[0011] (1) Add hydrochloric acid to the solvent, disperse evenly, then add SbCl3 and BiCl3, and stir ultrasonically until completely dissolved; the solvent is ethylene glycol;

[0012] (2) Add iron powder, and after the reaction is complete, add hydrochloric acid to remove the residual iron powder;

[0013] (3) Finally, the material was filtered with ethanol and water respectively, and then freeze-dried to obtain a two-dimensional SbBi alloy material.

[0014] The concentration of hydrochloric acid in step (1) is 2 mol / L; the volume ratio of hydrochloric acid to solvent is 1:2; the total molar ratio of SbCl3 and BiCl3 to the volume ratio of solvent is 1 mol: 200 mL; and the molar ratio of SbCl3 to BiCl3 is 9:1 to 1:9.

[0015] The molar ratio of the sum of SbCl3 and BiCl3 in step (1) to the iron powder in step (2) is 1:1.

[0016] The reaction time in step (2) is 2 hours.

[0017] The filtration in step (3) involves using ethanol and water three times each.

[0018] A two-dimensional SbBi alloy material prepared by the above-described preparation method.

[0019] The above-mentioned two-dimensional SbBi alloy material is used in lithium-ion batteries or potassium-ion batteries.

[0020] This invention relates to the large-scale synthesis of 2D-SbxBiy alloys via a simple one-step co-substitution reaction. By controlling the molar ratio of SbCl3 to BiCl3, SbxBiy alloys of any proportion can be synthesized. Performance comparisons demonstrate that 2D-Sb... 0.6 Bi 0.4 The alloy is the target product with the best performance ratio, and large-scale preparation can be achieved by increasing the amount of reaction products in the same proportion.

[0021] This invention combines the high capacity of Sb anodes and the long cycle stability of Bi anodes, and prepares novel two-dimensional SbBi alloys with different proportions by precisely controlling the ratio using a one-step co-substitution method at room temperature, wherein 2D-Sb 0.6 Bi 0.4 The alloy anode exhibits excellent potassium and lithium storage performance simultaneously without being combined with any other materials. Regarding potassium storage performance, it demonstrates excellent performance under stable cycling at a current of 0.5A; at 0.5A... -1 At the specified current density, after 100 cycles, its capacity remained at 460.70 mAh g. -1 Its capacity retention rate is as high as 97.30%, and the average decay rate per cycle is only 0.027%. Further confirmation of 2D-Sb was achieved through kinetic analysis, band structure, density of states, adsorption energy for potassium ions, and diffusion barrier calculations. 0.6 Bi 0.4The intrinsic reasons for the excellent performance of the alloy anode are: (1) the synergistic effect between Sb and Bi; (2) 2D-Sb 0.6 Bi 0.4 The alloy anode exhibits excellent kinetic performance; (3) it has a larger potassium ion adsorption energy and a lower diffusion energy barrier. This work provides more ideas and insights for the application of two-dimensional metal materials in energy storage, especially in lithium storage, which has been rarely reported.

[0022] The present invention has the following advantages and effects compared with the prior art:

[0023] (1) The 2D-SbxBiy alloy of the present invention can be synthesized on a large scale through a simple one-step co-substitution reaction, which is simpler, more convenient and less costly than other existing synthesis methods.

[0024] (2) The method of the present invention can synthesize SbBi alloys in any proportion by controlling the molar ratio of the raw materials, namely SbCl3 and BiCl3.

[0025] (3) The alloy synthesized by the co-substitution method in this invention has a lamellar morphology, which can greatly alleviate volume expansion, and the synthesized two-dimensional SbBi alloy has very good performance (where Sb 0.6 Bi 0.4 (It has the best performance), unlike other reported SbBi alloys that require composites with carbon, graphene, etc. to provide a more outstanding stability. Attached Figure Description

[0026] Figure 1 The images show the XRD patterns of the two-dimensional SbBi alloy materials obtained in Examples 1-9, the elemental Sb obtained in Example 10, and the elemental Bi obtained in Example 11.

[0027] Figure 2 SEM images of the two-dimensional SbBi alloy materials obtained in Examples 2, 4, 6 and 8;

[0028] Figure 3 The two-dimensional SbBi alloy material 2D-Sb obtained in Example 4 0.6 Bi 0.4 Graph of the 0.5A long-cycle performance of the alloy. Detailed Implementation

[0029] The following specific embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention.

[0030] Example 1: 2D-Sb 0.9 Bi 0.1 Alloy preparation

[0031] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.9 mol of SbCl3 and 0.1 mol of BiCl3, and sonicate until completely dissolved.

[0032] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0033] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.9 Bi 0.1 alloy.

[0034] Example 2: 2D-Sb 0.8 Bi 0.2 Alloy preparation

[0035] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.8 mol of SbCl3 and 0.2 mol of BiCl3, and sonicate until completely dissolved.

[0036] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0037] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.8 Bi 0.2 alloy.

[0038] Example 3: 2D-Sb 0.7 Bi 0.3 Alloy preparation

[0039] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.7 mol of SbCl3 and 0.3 mol of BiCl3, and sonicate until completely dissolved.

[0040] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0041] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.7 Bi 0.3 alloy.

[0042] Example 4: 2D-Sb 0.6 Bi 0.4Alloy preparation

[0043] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.6 mol of SbCl3 and 0.4 mol of BiCl3, and sonicate until completely dissolved.

[0044] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0045] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.6 Bi 0.4 alloy.

[0046] Example 5: 2D-Sb 0.5 Bi 0.5 Alloy preparation

[0047] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.5 mol of SbCl3 and 0.5 mol of BiCl3, and sonicate until completely dissolved.

[0048] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0049] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.5 Bi 0.5 alloy.

[0050] Example 6: 2D-Sb 0.4 Bi 0.6 Alloy preparation

[0051] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.4 mol of SbCl3 and 0.6 mol of BiCl3, and sonicate until completely dissolved.

[0052] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0053] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.4 Bi 0.6 alloy.

[0054] Example 7: 2D-Sb0.3 Bi 0.7 Alloy preparation

[0055] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.3 mol of SbCl3 and 0.7 mol of BiCl3, and sonicate until completely dissolved.

[0056] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0057] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.3 Bi 0.7 alloy.

[0058] Example 8: 2D-Sb 0.2 Bi 0.8 Alloy preparation

[0059] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.2 mol of SbCl3 and 0.8 mol of BiCl3, and sonicate until completely dissolved.

[0060] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0061] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.2 Bi 0.8 alloy.

[0062] Example 9: 2D-Sb 0.1 Bi 0.9 Alloy preparation

[0063] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 0.1 mol of SbCl3 and 0.9 mol of BiCl3, and sonicate until completely dissolved.

[0064] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0065] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain a powdered two-dimensional SbBi alloy material, which is 2D-Sb. 0.1 Bi 0.9 alloy.

[0066] Example 10: Preparation of 2D-Sb

[0067] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 1.0 mol of SbCl3 and sonicate until completely dissolved.

[0068] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0069] (3) Finally, the mixture was filtered three times with ethanol and water respectively, and then freeze-dried to obtain powdered two-dimensional Sb material, which is 2D-Sb element.

[0070] Example 11: Preparation of 2D-Bi

[0071] (1) Measure 200 mL of ethylene glycol into a three-necked flask, add 100 mL of 2 mol / L hydrochloric acid to the ethylene glycol, disperse evenly, then add 1.0 mol of BiCl3 and sonicate until completely dissolved.

[0072] (2) Slowly add 1 mol of iron powder, and after reacting for 2 hours, add hydrochloric acid to remove the residual iron powder;

[0073] (3) Finally, the material was filtered three times with ethanol and water respectively, and then freeze-dried to obtain powdered two-dimensional Bi material, which is 2D-Bi material.

[0074] To further demonstrate that the materials synthesized by the method of this invention are alloys, Examples 1-11 synthesized Sb, Bi, and nine different proportions of SbBi alloys using this method, and compared their XRD patterns. Figure 1 As shown, with the gradual increase of Bi content, the entire diffraction peak gradually shifts towards Bi, and the crystal structure of this spectrum corresponds one-to-one with the PDF card of the standard SbBi alloy.

[0075] SEM images of the two-dimensional SbBi alloy materials obtained in Examples 2, 4, 6, and 8 are shown below. Figure 2 As shown, for the alloy's two-dimensional structure, with increasing Bi content, the two-dimensional structure becomes smaller, thinner, and more uniformly distributed. Taking 2D-Sb as an example... 0.6 Bi 0.4 To illustrate the two-dimensional structure of the alloy, 2D-Sb 0.6 Bi 0.4 It is a nanoflower-like structure composed of many two-dimensional nanosheets, with the sheet-like structure being the most uniformly distributed.

[0076] The two-dimensional SbBi alloy material 2D-Sb obtained in Example 2 0.8Bi 0.2 The alloy exhibits long-cycle performance at 0.5A g. -1 At the specified current density, after 50 cycles, its capacity remained at 269.37 mAh g. -1 Its capacity retention rate is 73.8%, and the average decay rate per lap is 0.444%.

[0077] The two-dimensional SbBi alloy material 2D-Sb obtained in Example 6 0.4 Bi 0.6 The alloy exhibits long-cycle performance at 0.5A g. -1 At the specified current density, after 50 cycles, its capacity remained at 290.38 mAh g. -1 Its capacity retention rate is 77.4%, and the average decay rate per lap is 0.452%.

[0078] The two-dimensional SbBi alloy material 2D-Sb obtained in Example 8 0.2 Bi 0.8 The long-cycle performance of the alloy at 0.5A g is [not specified]. -1 At the specified current density, after 50 cycles, its capacity remained at 215.24 mAh g. -1 Its capacity retention rate is 94.1%, and the average decay rate per revolution is 0.118%.

[0079] The two-dimensional SbBi alloy material 2D-Sb obtained in Example 4 0.6 Bi 0.4 The long-cycle performance of the alloy at 0.5A is shown in the figure below. Figure 3 As shown, at 0.5Ag -1 At the specified current density, after 100 cycles, its capacity remained at 460.70 mAh g. -1 Its capacity retention rate is as high as 97.30%, and the average decay rate per revolution is only 0.027%.

[0080] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a two-dimensional SbBi alloy material, characterized in that... Follow these steps: (1) Add 2 mol / L hydrochloric acid to the solvent, disperse evenly, then add SbCl3 and BiCl3, and sonicate until completely dissolved; the solvent is ethylene glycol; the volume ratio of hydrochloric acid to solvent is 1:2; the total molar ratio of SbCl3 and BiCl3 to solvent is 1 mol: 200 mL; the molar ratio of SbCl3 to BiCl3 is 6:

4. (2) Add iron powder, react for 2 hours, then add hydrochloric acid to remove the residual iron powder; The molar ratio of the sum of SbCl3 and BiCl3 in step (1) to the iron powder in step (2) is 1:1; (3) Finally, the mixture was filtered with ethanol and water respectively, and then freeze-dried to obtain a two-dimensional SbBi alloy material; the two-dimensional SbBi alloy material is 2D-Sb 0.6 Bi 0.4 It is a nanoflower-like structure whose surface is composed of many two-dimensional nanosheets.

2. The preparation method according to claim 1, characterized in that: The filtration in step (3) involves using ethanol and water three times each.

3. A two-dimensional SbBi alloy material prepared by the preparation method described in claim 1 or 2.

4. The application of the two-dimensional SbBi alloy material according to claim 3 in potassium-ion batteries.

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