A method for preparing a flexible integrated electrode of antimony trioxide nanowire by combining impregnation method and pyrolysis method

Abstract

The application discloses a method for preparing a flexible integrated electrode of antimony trioxide nanowires by combining an impregnation method and a pyrogenic method. First, a flexible conductive substrate is immersed in an alcohol solution of a metal antimony salt, then taken out, cleaned and dried; the dried flexible conductive substrate is immersed in an alcohol solution of ammonia water again, then taken out, cleaned and dried again; the flexible conductive substrate taken out, cleaned and dried after the two immersions is heat-treated under a protective atmosphere to obtain the flexible integrated electrode of antimony trioxide nanowires. The flexible integrated electrode of antimony trioxide nanowires of the application grows a network structure of antimony trioxide nanowires on the flexible substrate, can effectively promote ion / charge transfer of the electrode, greatly improves the rate performance of the electrode material, and can realize the application of high-capacity and long-life lithium ion batteries. The preparation method of the application is simple in operation, low in cost and easy to control in the preparation process, and is favorable for safe production and equipment protection.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, and more specifically, to a method for preparing a flexible integrated electrode made of antimony trioxide nanowires. Background Technology

[0002] With the development of flexible wearable devices, the demand for flexible power supply devices (i.e., batteries) is constantly increasing. Flexible lithium-ion batteries, with their excellent electrochemical energy storage capacity and mechanical stability, play a crucial role in flexible wearable devices. Currently, the actual specific capacity of graphite anodes that can be commercially applied is close to the theoretical value (372 mAh / g), and this limited specific capacity cannot meet the market demand for high-energy-density batteries. Similarly, electrodes prepared by traditional slurry coating cannot meet the needs of flexible electronic devices. Therefore, seeking flexible lithium-ion battery anode materials with high theoretical specific capacity, high cycle stability, and low production cost is crucial to promoting the commercialization of flexible wearable devices.

[0003] Currently, materials applicable to lithium-ion battery anodes can be broadly categorized into carbon materials, alloy materials, silicon-based materials, tin-based materials, and antimony-based materials. Antimony-based materials, such as antimony alloys, antimony oxides, and antimony sulfides, have attracted significant attention as candidate anode materials for lithium-ion batteries. Among them, antimony trioxide (Sb₂O₃) stands out as a highly attractive anode material due to its high theoretical capacity (1109 mAh / g), low operating voltage, and good cycle stability.

[0004] However, Sb₂O₃ undergoes significant volume changes during charge and discharge, and the Li₂O generated during lithiation aggregates, affecting the first-cycle coulombic efficiency and causing substantial capacity loss. To address this issue, many effective methods have been proposed, such as constructing micron or nanostructures, modifying them through unique synthesis methods, and compositing them with conductive carbon matrices. Currently, the preparation of Sb₂O₃ electrodes with nanostructures composited with carbon materials mostly requires hydrothermal treatment or multiple high-temperature calcinations. The high preparation cost and complex process limit its large-scale application, and most preparation methods cannot meet the requirements of flexible batteries. Therefore, developing simple and cost-effective synthesis routes for high-performance anode materials used in flexible lithium-ion batteries remains urgent. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing a flexible integrated antimony trioxide nanowire electrode by combining impregnation and pyrolysis methods. The synthesis method of this invention is simple to operate, low in cost, and easy to control during the preparation process, which is beneficial for safe production and equipment protection. This invention achieves a flexible electrode by uniformly growing an antimony trioxide nanowire network structure on a flexible substrate, effectively promoting ion / charge transfer and significantly improving the rate performance of the electrode material. The lithium-ion battery anode material of this invention effectively alleviates the volume expansion effect during charge and discharge, improves lithium storage capacity and electronic conductivity, and enables flexible lithium-ion batteries to have high specific capacity and good cycle stability. As a negative electrode, and especially as a flexible electrode, this invention can be applied in high-capacity, long-life, and particularly flexible lithium-ion batteries.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] This invention provides a method for preparing a flexible integrated electrode of antimony trioxide nanowires by combining impregnation and pyrolysis methods, comprising the following steps:

[0008] a) Immerse a clean, flexible conductive substrate in an alcoholic solution of antimony salts until fully soaked, then remove, clean, and dry it.

[0009] b) Immerse the dried flexible conductive substrate obtained in step a) in an alcoholic solution of ammonia water for a thorough soaking, then remove, clean and dry it;

[0010] c) The dried flexible conductive substrate obtained in step b) is pyrolyzed under inert gas protection to obtain a flexible integrated electrode in which antimony trioxide is uniformly grown on the substrate in a nanowire network structure.

[0011] In this invention, in step a), the flexible conductive substrate is carbon cloth.

[0012] In this invention, in step a), the concentration of the antimony salt in alcohol solution is 0.2~2 mmol / mL; wherein the antimony salt is selected from one or more of antimony chloride, antimony acetate or antimony nitrate, and the alcohol solvent is selected from one or more of ethanol, propylene glycol or isopropanol.

[0013] In this invention, in step b), the volume ratio of concentrated ammonia to alcohol in the ammonia solution is 1:4 to 1:6; wherein the alcohol solvent is any one of ethanol, propylene glycol, and isopropanol.

[0014] In this invention, in step a), the soaking temperature is 0 ~ 40℃ and the soaking time is 2 ~ 7 days; in step b), the soaking temperature is 0 ~ 40℃ and the soaking time is 3 ~ 10 h.

[0015] In this invention, in steps a) and b), the conductive substrate is cleaned with an alcohol solvent, mainly to remove unreacted substances from the surface of the flexible conductive substrate; the drying temperature is 40 ~ 80℃, and the drying time is 1 ~ 12 h.

[0016] In this invention, in step c), the pyrolysis temperature is 250~400℃, the pyrolysis time is 2~4 h, and the inert gas is one or both of argon and nitrogen.

[0017] The present invention also provides a flexible integrated electrode of antimony trioxide nanowires prepared by the above method, wherein the flexible integrated electrode has a nanowire network structure; in a specific embodiment, the antimony trioxide nanowires are loaded on a flexible substrate, the diameter of the antimony trioxide nanowires is between 20 and 60 nm and the length is between 1 and 2.2 μm, and the nanowires are interwoven to form a uniform network structure.

[0018] Furthermore, the present invention provides a lithium-ion battery comprising a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the aforementioned flexible integrated antimony trioxide nanowire electrode is directly used as the negative electrode. Preferably, the lithium-ion battery is a flexible lithium-ion battery.

[0019] Compared with the prior art, the present invention has the following beneficial and substantial features and significant advantages:

[0020] 1. This invention employs a combination of impregnation and thermal decomposition methods to prepare a flexible integrated antimony trioxide nanowire electrode. The electrode features a uniformly grown antimony trioxide nanowire network structure on a carbon cloth substrate. The spacing between the antimony trioxide nanowires effectively buffers the volume expansion of the material during charge and discharge, improving its cycle stability. The carbon cloth substrate effectively promotes ion / charge transfer within the electrode, enhancing its rate performance. The prepared flexible integrated electrode eliminates the need for non-electrochemically active materials such as binders, thereby increasing battery energy density.

[0021] 2. This method is simple to operate and highly operable. The first two steps can be carried out at or near room temperature, which greatly reduces energy consumption. It can uniformly grow antimony trioxide nanowire network structures on the surface of carbon cloth without the need for hydrothermal treatment, which helps to further expand production.

[0022] 3. The electrode material prepared according to this invention was tested. Experimental results show that, under constant current charge-discharge at a current density of 1.0 A / g, the specific capacity remains stable at a level of not less than 986 mAh / g after 200 cycles. Applying the preparation method of this invention to the battery field allows for the large-scale fabrication of flexible integrated electrodes, suitable for industrial production. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Of course, the drawings in the following description are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 The X-ray diffraction pattern is that of the negative electrode material prepared in Example 1.

[0025] Figure 2 This is a bending test diagram of the negative electrode material prepared in Example 1.

[0026] Figure 3 This is a scanning electron microscope (SEM) image of a single carbon fiber loaded with antimony trioxide nanowires for the negative electrode material prepared in Example 1.

[0027] Figure 4 This is a scanning electron microscope image of antimony trioxide nanowires loaded on the surface of carbon cloth using the negative electrode material prepared in Example 1.

[0028] Figure 5 This is a transmission electron microscope (TEM) image of antimony trioxide nanowires on the surface of the negative electrode material prepared in Example 1.

[0029] Figure 6 This is a rate performance diagram of the negative electrode material prepared in Example 1 when applied to a lithium-ion battery.

[0030] Figure 7 The charge-discharge cycle curves of the negative electrode material prepared in Example 1 when applied to a lithium-ion battery at a current density of 0.1 A / g are shown.

[0031] Figure 8 The charge-discharge cycle curves of the negative electrode material prepared in Example 1 when applied to a lithium-ion battery at a current density of 0.5 A / g are shown.

[0032] Figure 9 The charge-discharge cycle curves of the negative electrode material prepared in Example 1 when applied to a lithium-ion battery at a current density of 1.0 A / g are shown. Detailed Implementation

[0033] The negative electrode material prepared by the preparation technology used in the following embodiments of the present invention can effectively alleviate the volume expansion of the material during charge and discharge, and improve the cycle stability of the material; the carbon cloth substrate can fully promote ion / charge transfer within the electrode, improving the rate performance of the electrode material. The prepared flexible integrated electrode can reduce the use of non-electrochemically active materials such as binders, and improve the battery energy density.

[0034] The present invention, as described in the following embodiments, employs a combination of impregnation and thermal decomposition methods to uniformly grow antimony trioxide nanowire networks on the surface of a carbon cloth substrate. Furthermore, this method is simple to operate, highly operable, and the first two reaction steps require relatively low temperatures, allowing them to be carried out at ambient temperatures, thus significantly reducing energy consumption. It enables large-scale fabrication of flexible integrated electrodes and is suitable for industrial production.

[0035] The following embodiments of the present invention do not impose any special limitations on the counter electrode, separator, battery casing, electrolyte, etc. The counter electrode can be a lithium sheet; the separator can be a polypropylene (PP) microporous separator; and the electrolyte is a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC). Specifically, the present invention simply involves directly slicing the flexible integrated electrode into an electrode sheet; using a lithium sheet as the counter electrode; using a two-component mixed solvent of 1 mol / L lithium hexafluorophosphate (LiFP6) EC:DEC = 1:1 as the electrolyte; and assembling a CR2016 analog battery using a PP microporous separator.

[0036] The following embodiments of the present invention employ constant current charge-discharge experiments to test the cycle performance of the assembled lithium-ion battery, with the charge-discharge voltage limited to 0.01 ~ 3 V. The electrochemical performance of the battery is tested using a CT2001A battery testing system from Wuhan Landian Electronics Co., Ltd., under room temperature conditions.

[0037] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, describes a method for preparing a flexible integrated antimony trioxide nanowire anode by combining impregnation and pyrolysis methods, and the high-capacity, long-life potassium-ion battery performance. However, this should not be construed as limiting the scope of protection of the present invention.

[0038] The above solution will be further explained below with reference to specific embodiments. The preferred embodiments of the present invention are described in detail below.

[0039] Example 1

[0040] In this embodiment, a method for preparing a flexible integrated electrode of antimony trioxide nanowires by combining impregnation and pyrolysis includes the following steps:

[0041] a) Dissolve 10 mmol of antimony trichloride in 20 mL of ethanol to prepare a 0.5 mol / L antimony trichloride ethanol solution. Immerse a clean carbon cloth in the solution and soak it at 20°C for 4 days. Then take it out, wash it with ethanol to remove unreacted substances from the surface of the carbon cloth, and dry it at 60°C for 2 h.

[0042] b) Immerse the dried carbon cloth obtained in step a) in an ethanol solution of ammonia water and ethanol at a volume ratio of 1:5, soak it at 20°C for 4 h, then take it out, wash it with ethanol to remove unreacted substances from the surface of the carbon cloth, and dry it at 60°C for 2 h.

[0043] c) The dried carbon cloth obtained in step b) is heated to 300℃ and held for 2 hours under nitrogen protection, then cooled to room temperature to obtain the carbon cloth loaded with antimony trioxide nanowires, i.e., the flexible integrated electrode of antimony trioxide nanowires; its XRD is as follows. Figure 1 As shown, the characteristic peaks correspond to the standard card JCPDS:43-1071. The resulting integrated electrode was subjected to a bending test, as shown... Figure 2 As shown, the material exhibits excellent flexibility and mechanical properties. Its scanning electron microscope image is shown below. Figure 3 , Figure 4 As shown, the antimony trioxide nanowires exhibit a uniform network structure in the field of view. The antimony trioxide nanowires are in close contact with the carbon cloth substrate, ensuring the structural stability of the flexible electrode material. Its transmission electron microscope image is shown below. Figure 5 As shown, the prepared antimony trioxide nanowires have a diameter of 20-60 nm and a length of 1-2.2 μm, and exhibit uniform structure and size.

[0044] The rate performance of the prepared integrated electrode was characterized. When the current density gradually increased from 0.1 A / g to 0.2, 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 A / g, the discharge specific capacity of the obtained integrated flexible electrode was 1459, 1278, 1126, 971, 779, 649, 562, and 471 mAh / g, respectively. When the current density returned to 0.1 A / g, the discharge specific capacity also returned to 1303 mAh / g. The results are as follows: Figure 6 As shown, the material exhibits good rate performance. The obtained flexible integrated electrode was subjected to constant current charge-discharge testing at a current density of 0.1 A / g, and the results are as follows... Figure 7 As shown, after 100 cycles, the specific capacity remained at 1135 mAh / g, demonstrating high specific capacity and excellent cycle stability. The constant current charge-discharge performance of the lithium-ion battery in this invention was also tested at a current density of 0.5 A / g. After 200 cycles, the specific capacity remained at 1008 mAh / g, as shown in the results. Figure 8 As shown. The lithium-ion battery of this invention has a specific capacity of no less than 986 mAh / g after 200 cycles of constant current charge-discharge at a current density of 1.0 A / g, as shown in the figure. Figure 9 As shown.

[0045] Example 2

[0046] In this embodiment, a method for preparing a flexible integrated electrode of antimony trioxide nanowires by combining impregnation and pyrolysis includes the following steps:

[0047] a) Dissolve 15 mmol of antimony nitrate in 15 mL of propylene glycol to prepare a 1.0 mol / L antimony nitrate propylene glycol solution. Immerse a clean carbon cloth in the solution and soak it at 20°C for 3.5 days. Then remove the cloth, wash it with propylene glycol to remove unreacted substances from the surface of the carbon cloth, and dry it at 60°C for 2 h.

[0048] b) Immerse the dried carbon cloth obtained in step a) in a propylene glycol solution of ammonia and propylene glycol at a volume ratio of 1:5. After soaking at 20°C for 3 h, remove it, wash it with ethanol to remove unreacted substances from the surface of the carbon cloth, and dry it at 60°C for 2 h.

[0049] c) The dried carbon cloth obtained in step b) is thermally decomposed at 350°C for 2 h under nitrogen protection to finally obtain a flexible integrated electrode of antimony trioxide nanowires.

[0050] The electrode material prepared in this embodiment exhibits a uniform network structure, with antimony trioxide nanowires uniformly grown on a carbon cloth substrate. Bending tests on the integrated electrode prepared in this embodiment revealed excellent flexibility. Charge-discharge cycle tests showed that after 200 cycles at a current density of 1.0 A / g, the capacity remained at 967 mAh / g, demonstrating high specific capacity and good cycle stability. The antimony trioxide nanowire carbon cloth prepared in this embodiment exhibits excellent electrochemical performance and good mechanical properties, meeting the requirements of flexible batteries and suitable for large-scale industrial production.

[0051] Example 3

[0052] In this embodiment, a method for preparing a flexible integrated electrode of antimony trioxide nanowires by combining impregnation and pyrolysis includes the following steps:

[0053] a) Dissolve 10 mmol of antimony nitrate in 25 mL of isopropanol to prepare a 0.4 mol / L antimony nitrate isopropanol solution. Immerse the clean carbon cloth in the solution and soak it at 25°C for 6 days. Then take it out, wash it with isopropanol to remove unreacted substances from the surface of the carbon cloth, and dry it at 60°C for 4 h.

[0054] b) Immerse the dried carbon cloth obtained in step a) in an isopropanol solution of ammonia water and isopropanol with a volume ratio of 1:4.5, soak at 25°C for 5 h, then take it out, wash it with isopropanol to remove unreacted substances from the surface of the carbon cloth, and dry it at 55°C for 4 h.

[0055] c) The dried carbon cloth obtained in step b) is thermally decomposed at 380°C for 3 h under nitrogen protection to finally obtain a flexible integrated electrode of antimony trioxide nanowires.

[0056] The electrode material prepared in this embodiment exhibits a uniform network structure, with antimony trioxide nanowires uniformly grown on a carbon cloth substrate. Bending tests on the integrated electrode prepared in this embodiment revealed excellent flexibility. Charge-discharge cycling tests showed that after 200 cycles at a current density of 1.0 A / g, the capacity remained at 906 mAh / g, demonstrating high specific capacity and good cycle stability. The antimony trioxide nanowire carbon cloth prepared in this embodiment exhibits excellent electrochemical performance and good mechanical properties, meeting the requirements of flexible batteries and suitable for large-scale industrial production.

[0057] Example 4

[0058] In this embodiment, a method for preparing a flexible integrated electrode of antimony trioxide nanowires by combining impregnation and pyrolysis includes the following steps:

[0059] a) Dissolve 15 mmol of antimony acetate in 10 mL of butanediol to prepare a 1.5 mol / L antimony acetate butanediol solution. Immerse a clean carbon cloth in the solution and soak it at 35°C for 4.5 days. Then remove the cloth, wash it with isopropanol to remove unreacted substances from the surface of the carbon cloth, and dry it at 65°C for 2 h.

[0060] b) Immerse the dried carbon cloth obtained in step a) in an isopropanol solution of ammonia water and isopropanol with a volume ratio of 1:4.5, soak at 35°C for 3.5 h, then take it out, wash it with isopropanol to remove unreacted substances from the surface of the carbon cloth, and dry it at 50°C for 9 h.

[0061] c) The dried carbon cloth obtained in step b) is thermally decomposed at 280°C for 4 h under nitrogen protection to finally obtain a flexible integrated electrode of antimony trioxide nanowires.

[0062] The electrode material prepared in this embodiment exhibits a uniform network structure, with antimony trioxide nanowires uniformly grown on a carbon cloth substrate. Bending tests on the integrated electrode prepared in this embodiment revealed excellent flexibility. Charge-discharge cycle tests on the product prepared in this embodiment showed that after 200 cycles at a current density of 1.0 A / g, the capacity remained at 989 mAh / g, demonstrating high specific capacity and good cycle stability. The antimony trioxide nanowire carbon cloth prepared in this embodiment exhibits excellent electrochemical performance and good mechanical properties, meeting the requirements of flexible batteries and suitable for large-scale industrial production.

[0063] The above embodiments of the present invention provide a method for preparing a flexible integrated antimony trioxide nanowire electrode by combining an impregnation method and a pyrolysis method, and its application in high-capacity, long-life lithium-ion battery performance. First, carbon cloth is immersed in an alcohol solution of antimony metal salts, such as antimony trichloride or antimony nitrate in ethanol or propylene glycol, then removed, cleaned, and dried. Next, the dried carbon cloth is immersed again in an alcohol solution of ammonia, such as ethanol or isopropanol, and again removed, cleaned, and dried. Finally, the carbon cloth, after two immersions, is heat-treated under a protective atmosphere to thermally decompose and obtain the flexible integrated antimony trioxide nanowire electrode, which is then used as a flexible negative electrode for lithium-ion batteries. The flexible integrated antimony trioxide nanowire electrode of the present invention uses a carbon cloth substrate to uniformly grow an antimony trioxide nanowire network structure. The gaps between the antimony trioxide nanowires effectively alleviate the volume expansion of antimony trioxide during lithium-ion insertion and extraction. The composite of antimony trioxide nanowires and a conductive substrate effectively promotes ion / charge transfer in the electrode, greatly improving the rate performance of the electrode material. The antimony trioxide nanowire integrated electrode of this invention maintains a specific capacity of 986 mAh / g after 200 cycles at a high current of 1 A / g, demonstrating excellent cycle stability and high specific capacity. Compared with the prior art, the first two steps of the method in the above embodiments of this invention can be carried out at room temperature or near room temperature, with low energy consumption and low requirements for production equipment, enabling mass production. The resulting flexible integrated antimony trioxide nanowire electrode has excellent electrochemical performance and flexibility, meeting the requirements of flexible batteries.

[0064] The above description is merely an illustration of the embodiments of the present invention in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a flexible integrated electrode of antimony trioxide nanowires by combining impregnation and pyrolysis, characterized in that, Includes the following steps: a) Immerse a clean, flexible conductive substrate in an alcoholic solution of antimony salts until fully soaked, then remove, clean, and dry it. b) Immerse the dried flexible conductive substrate obtained in step a) in an alcoholic solution of ammonia water until fully soaked, then remove, clean and dry it; c) The dried flexible conductive substrate obtained in step b) is pyrolyzed under inert gas protection to obtain a flexible integrated electrode in which antimony trioxide is uniformly grown on the substrate in a nanowire network structure.

2. The method according to claim 1, characterized in that, In step a), the flexible conductive substrate is carbon cloth.

3. The method according to claim 1, characterized in that, In step a), the concentration of the antimony salt in alcohol solution is 0.2~2 mmol / mL; wherein the antimony salt is selected from one or more of antimony chloride, antimony acetate or antimony nitrate, and the alcohol solvent is selected from one or more of ethanol, propylene glycol or isopropanol.

4. The method according to claim 1, characterized in that, In step b), the volume ratio of concentrated ammonia to alcohol in the ammonia solution is 1:4 to 1:6; wherein the alcohol solvent is any one of ethanol, propylene glycol, or isopropanol.

5. The method according to claim 1, characterized in that, In step a), the soaking temperature is 0 ~ 40℃ and the soaking time is 2 ~ 7 days; or the soaking temperature is 0 ~ 40℃ and the soaking time is 3 ~ 10 hours.

6. The method according to claim 1, characterized in that, In steps a) and b), the conductive substrate is cleaned with an alcohol solvent; the drying temperature is 40 ~ 80℃ and the drying time is 1 ~ 12h.

7. The method according to claim 1, characterized in that, In step c), the pyrolysis temperature is 250~400℃, the pyrolysis time is 2~4 h, and the inert gas is one or both of argon and nitrogen.

8. A flexible integrated antimony trioxide nanowire electrode prepared according to any one of claims 1 to 7, characterized in that, The flexible integrated electrode has a nanowire network structure.

9. A lithium-ion battery, comprising a positive electrode, a negative electrode, a separator, and an electrolyte, characterized in that, The antimony trioxide nanowire flexible integrated electrode as described in claim 8 is used as the negative electrode.

10. The lithium-ion battery according to claim 9, characterized in that, The lithium-ion battery is a flexible lithium-ion battery.

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