A conductive polymer-coated antimony selenide / ordered mesoporous carbon composite negative electrode material, a preparation method and application thereof

Abstract

The application discloses a kind of electrically conductive polymer coated antimony selenide / ordered mesoporous carbon composite negative electrode material and its preparation method and application, belong to lithium ion battery negative electrode material preparation technical field.Ordered mesoporous carbon is added in antimony selenide precursor liquid and is mixed uniformly, and precursor mixed solution is obtained;The precursor mixed solution is kept at 180 DEG C for 24 h, and is cooled to room temperature, and the precipitate is collected by centrifugation, washing, freeze-drying, in inert atmosphere, with 3 DEG C / min heating rate to 500 DEG C, annealing, and Sb2Se3@OMC composite material is obtained;Ammonium persulfate and Sb2Se3@OMC composite material are added to the mixed solution of 3,4-ethylenedioxythiophene and dilute hydrochloric acid and are mixed uniformly, and are dried, to obtain electrically conductive polymer coated antimony selenide / ordered mesoporous carbon composite negative electrode material.In the electrode made of the composite material, antimony selenide nanoparticles are uniformly distributed in ordered mesoporous carbon and surface, and are finally coated by electrically conductive polymer, and have excellent long cycle stability and rate performance when used as lithium ion battery negative electrode.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery anode material preparation technology, specifically relating to a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material, its preparation method, and its application. Background Technology

[0002] Compared to traditional energy sources like coal and oil, renewable energy sources such as wind and solar power are better able to meet the application needs of the new era. Advanced electrochemical energy storage devices are a crucial component of this transformation. Over the past few decades, lithium-ion batteries, with their high energy density, low self-discharge rate, and long cycle life, have been widely used in electrochemical energy storage devices, such as digital cameras, laptops, and electric vehicles. The most widely used graphite-based anode in lithium-ion batteries has approached its theoretical limit (372 mAh g⁻¹). -1 This cannot meet the current social development demand for high energy density.

[0003] Antimony selenide (Sb₂Se₃) has a high theoretical capacity (670 mAh g⁻¹). -1 Antimony selenide has attracted much attention due to its suitability for operating potential and the synergistic effect between selenium and antimony, which significantly improves the cycle stability compared to pure selenium and pure antimony materials. However, antimony selenide undergoes drastic volume changes during lithium extraction / intercalation, causing mechanical strain and thus affecting battery performance.

[0004] To address the technical problem that antimony selenide undergoes drastic volume changes during lithium insertion / extraction, leading to mechanical strain and thus affecting battery performance, there is an urgent need to conduct modification research on antimony selenide to develop a low-cost, high-capacity, long-life, and high-power-density antimony selenide-based lithium-ion battery anode material. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material, its preparation method and application, so as to solve the technical problem that the existing antimony selenide undergoes drastic volume changes during the lithium deintercalation / intercalation process, which causes mechanical strain and thus affects battery performance.

[0006] To achieve the above objectives, the present invention employs the following technical solution: The first aspect of this invention discloses a method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material, comprising the following steps: 1) Add ordered mesoporous carbon to antimony selenide precursor solution and mix well to obtain precursor mixture; 2) The precursor mixture was kept at 180℃ for 24 h, cooled to room temperature, centrifuged to collect the precipitate, washed, freeze-dried, and annealed at a heating rate of 3℃ / min to 500℃ under an inert atmosphere to obtain the Sb2Se3@OMC composite material. 3) Add ammonium persulfate and Sb2Se3@OMC composite material to a mixed solution of 3,4-ethylenedioxythiophene and dilute hydrochloric acid, mix well, and dry to obtain conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material.

[0007] Preferably, in step 1), the ordered porous carbon is CMK-3, CMK-5, or a nitrogen-doped derivative thereof.

[0008] Preferably, in step 1), the method for preparing the antimony selenide precursor solution is as follows: antimony trichloride powder is added to a mixed solution of deionized water and ethanol and mixed evenly to obtain an antimony trichloride solution; selenium powder and sodium borohydride powder are dissolved in deionized water to obtain a NaHSe solution; under stirring, the NaHSe solution is added to the antimony trichloride solution and mixed evenly to obtain the antimony selenide precursor solution.

[0009] More preferably, the volume ratio of deionized water to ethanol is 6.0:(0.9~1.1), and the molar ratio of antimony trichloride to ethanol is (0.9~1.1):171.3.

[0010] Preferably, the molar ratio of selenium powder to sodium borohydride powder is (2.9~3.1):5.0; the volume ratio of ethanol in the antimony trichloride solution to deionized water in the NaHSe solution is 2.0:(0.9~1.1); and the molar ratio of antimony trichloride in the antimony trichloride solution to selenium in the antimony selenide precursor solution is (0.9~1.1):1.5.

[0011] Preferably, in step 1), the total mass ratio of the source material antimony trichloride to selenium in the ordered mesoporous carbon and antimony selenide precursor solution is (1.9~2.1):7.0.

[0012] Preferably, in step 2), the mass ratio of Sb2Se3@OMC composite material to ammonium persulfate is 2.0:(0.9~1.1), and the molar ratio of 3,4-ethylenedioxythiophene to ammonium persulfate is (0.9~1.1):1.0.

[0013] In a second aspect, the present invention discloses a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared by the above-described method.

[0014] A third aspect of the present invention discloses the application of the above-mentioned conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material in the preparation of lithium-ion batteries.

[0015] A fourth aspect of the present invention discloses a working electrode sheet for a lithium-ion secondary battery, comprising a current collector and an active material coating coated on the current collector, wherein the active material coating contains a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite negative electrode material prepared by the above-mentioned preparation method.

[0016] A fifth aspect of the present invention discloses a lithium-ion secondary battery, which is assembled from a counter electrode, a separator, an electrolyte and the working electrode sheet of the lithium-ion secondary battery described above.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material. 1) Using antimony selenide (Sb₂Se₃) precursor solution as the reaction raw material ensures that antimony selenide is uniformly dispersed at the nanoscale, allowing for sufficient wetting and efficient contact with ordered mesoporous carbon, which has a high specific surface area and ordered mesoporous structure. This effectively avoids problems such as insufficient contact and uneven distribution caused by powder agglomeration, and facilitates the uniform loading of antimony selenide into the pore structure of the mesoporous carbon. 2) The ordered mesoporous carbon has a high specific surface area and ordered mesoporous structure, with an average pore size of only 2~50 nm, providing sufficient loading sites for Sb₂Se₃ nanoparticles. This achieves uniform dispersion of the active material, and the mesoporous structure constructs a three-dimensional interconnected ion transport channel, significantly shortening the Li₂Se₃ ion transport time. +3) 3,4-Ethylenedioxythiophene undergoes oxidative polymerization under the action of ammonium persulfate to form the conjugated polymer poly(3,4-ethylenedioxythiophene) (PEDOT). PEDOT has advantages such as high conductivity and good thermal stability. The PEDOT coating can improve the interfacial compatibility between the electrolyte and the active material, reduce side reactions during cycling, and prevent the formation of an excessively thick solid electrolyte interface; 4) Antimony selenide is coated with ordered mesoporous carbon and PEDOT. Antimony selenide nanoparticles are uniformly distributed in the ordered mesoporous carbon and coated with the conductive polymer PEDOT. The bilayer structure of ordered mesoporous carbon and PEDOT serves as a robust volume expansion buffer layer and a conductivity enhancement layer, which can suppress large volume expansion during cycling, thereby improving the cycle life of Sb2Se3-based anode materials. This method is simple, safe, environmentally friendly, and suitable for large-scale clean production. The conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material obtained based on this method exhibits distinct structural characteristics. Antimony selenide is confined within ordered mesoporous carbon. Since the average pore size of the ordered mesoporous carbon is only 2-50 nm, nano-sized antimony selenide particles can be achieved. The structural stress generated by these particles during multiple lithium insertion / extraction processes is smaller compared to larger antimony selenide particles, making them less prone to structural collapse. They act as a robust physical barrier to buffer the volume expansion of antimony selenide and provide three-dimensional conductive channels. Experiments demonstrate that the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared by the above method, under the synergistic effect of the ordered mesoporous carbon and the PEDOT layer, exhibits strong cycle stability, high specific capacity, and excellent rate performance. When used as an anode in lithium-ion batteries, it demonstrates excellent long-term cycle stability and superior rate performance.

[0018] This invention also discloses the application of the aforementioned conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material in lithium-ion batteries. When used as an anode material in lithium-ion batteries, it undergoes an alloying reaction during discharge. During this reaction, the mesoporous spaces of the ordered mesoporous carbon can accommodate the volume expansion and contraction of the active material, preventing material agglomeration, pulverization, or detachment, significantly improving the long-cycle stability of the electrode and constructing a three-dimensionally interconnected ion transport channel. The conductive polymer coating layer has excellent flexibility and elasticity, acting like an "elastic membrane" to encapsulate the Sb₂Se₃@OMC composite system, improving the interfacial compatibility between the electrolyte and the active material, reducing side reactions during cycling, and preventing the formation of an excessively thick solid electrolyte interface. The ordered mesoporous carbon and the conductive polymer synergistically improve cycle stability. Given these characteristics, this material is highly suitable for use as an anode material in lithium-ion batteries. Attached Figure Description

[0019] Figure 1The images are TEM images of the Sb2Se3@CMK-3 composite material prepared in Example 1 of the present invention; wherein, (a) is a TEM image of the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material, and (b) is an enlarged view of the part in the yellow box in (a). Figure 2 The XRD pattern of the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared in Example 1 of the present invention; Figure 3 The Raman spectrum of the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared in Example 1 of the present invention; Figure 4 This is the first charge-discharge curve of the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared in Example 1 of the present invention in a lithium-ion battery with a current density of 0.1 A / g. Figure 5 This is a graph showing the cycling performance of the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared in Example 1 of this invention in a lithium-ion battery with a current density of 0.5 A / g. Figure 6 This is a rate performance diagram of the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared in Example 1 of this invention in a lithium-ion battery. Detailed Implementation

[0020] To enable those skilled in the art to understand the features and effects of the present invention, the following description and definitions are only general descriptions of the terms and expressions mentioned in the specification. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0021] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0022] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0023] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0024] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0025] This invention provides a method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material, comprising the following steps: Step 1: Add antimony trichloride powder to a mixed solvent of deionized water and ethanol, stir for 30 min to obtain an antimony trichloride solution; In the mixed solvent of deionized water and ethanol, the volume ratio of deionized water to ethanol is 6.0:(0.9~1.1), and the molar ratio of antimony trichloride to ethanol is (0.9~1.1):171.3. Step 2: Dissolve selenium powder and sodium borohydride powder in deionized water at a molar ratio of (2.9~3.1):5.0 to prepare a transparent NaHSe solution; while stirring, add the transparent NaHSe solution to the antimony trichloride solution prepared in step 1, and continue stirring for 20 min to obtain the antimony selenide precursor solution. The volume ratio of ethanol in the antimony trichloride solution to deionized water in the NaHSe solution is 2.0:(0.9~1.1); the molar ratio of antimony trichloride in the antimony trichloride solution to selenium in the antimony selenide precursor solution is (0.9~1.1):1.5. Step 3: Add ordered mesoporous carbon (OMC) to the antimony selenide precursor solution obtained in Step 2, and continue stirring for 20-40 min to obtain a precursor mixture; The ordered mesoporous carbon includes, but is not limited to, KAIST-type mesoporous carbon-3 (Carbon Mesostructured by KAIST-3, CMK-3), KAIST-type mesoporous carbon-5 (Carbon Mesostructured by KAIST-5, CMK-5), and their nitrogen-doped derivatives; the mass ratio of the ordered mesoporous carbon to the total mass of antimony trichloride and selenium in the antimony selenide precursor solution is (1.9~2.1):7.0; Step 4: Transfer the precursor mixture obtained in Step 3 to a reactor, heat it to 180℃ in an oven and keep it at that temperature for 24 h. After removing it, let it cool naturally to room temperature, centrifuge it, and collect the black precipitate. Wash the black precipitate alternately with deionized water and ethanol, freeze dry it for 12 h, and then anneal it at 500℃ for 2 h under an Ar atmosphere at a rate of 3℃ / min to obtain the Sb2Se3@OMC composite material. Step 5: Add the Sb2Se3@OMC composite material obtained in Step 4 and ammonium persulfate to a mixed solution of 3,4-ethylenedioxythiophene (PEDOT) and 0.1 M hydrochloric acid at a mass ratio of 2.0:(0.9~1.1). Stir for 10~12 h, wash with water and ethanol, and dry in an oven at 80℃ to obtain a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material (Sb2Se3@OMC / PEDOT). The molar ratio of 3,4-ethylenedioxythiophene to ammonium persulfate is (0.9~1.1):1.0.

[0026] The present invention also provides a working electrode sheet for a lithium-ion secondary battery, comprising a current collector and an active material coating coated on the current collector. The current collector includes, but is not limited to, copper foil. The active material coating comprises a binder, a conductive agent, and a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite material prepared by the above method in a mass ratio of 1:1:8. The binder includes, but is not limited to, polyvinylidene fluoride (PVDF), and the conductive additive includes, but is not limited to, conductive carbon black.

[0027] The present invention also provides a lithium-ion secondary battery, which is assembled from a counter electrode, a separator, an electrolyte and the aforementioned working electrode sheet of a lithium-ion secondary battery.

[0028] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading this description, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0029] The following examples use conventional instruments and equipment in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. Information on some of the raw materials used in the following examples is as follows: Antimony trichloride powder, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., item number A112096-25g; Selenium powder, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., item number S434041-50g; Sodium borohydride powder, purchased from Sinopharm Chemical Reagent Co., Ltd., item number 16940-66-2; Ordered mesoporous carbon CMK-3, CMK-5, and nitrogen-doped CMK-3 were purchased from Nanjing Xianfeng Nanomaterials Technology Co., Ltd., item numbers 100423, 100424, and 100999, respectively. All other raw materials used, unless otherwise stated, are conventional commercially available products with specifications in the art.

[0030] Example 1 1. Preparation of conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material 1) Add 0.2258 g of antimony trichloride powder to a mixed solvent of 60 mL of deionized water and 9.0 mL of ethanol, and stir for 30 min to obtain an antimony trichloride solution; 2) Accurately weigh 0.1066 g of selenium powder and 0.088 g of sodium borohydride powder, and dissolve them together in 4.05 mL of deionized water to prepare a transparent NaHSe solution; while stirring, add the transparent NaHSe solution to the antimony trichloride solution obtained in step 1), and continue stirring for 20 min to obtain the antimony selenide precursor solution. 3) Add 0.09 g of CMK-3 to the antimony selenide precursor solution obtained in step 2), and continue stirring for 20 min to generate a precursor mixture; 4) Transfer the precursor mixture obtained in step 3) to an autoclave, heat it to 180℃ in an oven and keep it at that temperature for 24 hours. After removing it, let it cool naturally to room temperature and centrifuge it to collect the black precipitate. Wash the black precipitate with deionized water and ethanol alternately 6 times, and freeze-dry it for 12 hours to obtain a black powder. Anneal the black powder in an Ar atmosphere at a temperature of 3℃ / min to 500℃ for 2 hours to obtain the Sb2Se3@CMK-3 composite material.

[0031] The microstructure and structure of the obtained Sb2Se3@CMK-3 composite material were observed using transmission electron microscopy (TEM) at an accelerating voltage of 200 kV, and TEM images were obtained, as shown below. Figure 1 As shown, antimony selenide is uniformly confined within CMK-3, indicating that antimony selenide and CMK-3 have achieved good composite formation.

[0032] 5) Using a pipette, take 17.4 μL of 3,4-ethylenedioxythiophene and add it to 40 mL of 0.1 M hydrochloric acid. Stir vigorously at room temperature for 0.5 h to obtain a mixed solution of EDOT and hydrochloric acid. 6) Take 75 mg of the Sb2Se3@CMK-3 composite material prepared in step 4) and 33.8 mg of ammonium persulfate, add them to the mixed solution of EDOT and hydrochloric acid obtained in step 5), and stir at room temperature for 10 h; filter the stirred sample, wash it with deionized water and anhydrous ethanol, and finally dry it in a vacuum drying oven at 80℃ for 12 h to obtain the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material (Sb2Se3@CMK-3 / PEDOT).

[0033] After thoroughly grinding the obtained Sb2Se3@CMK-3 / PEDOT, it was evenly spread on the sample stage and placed in an X-ray diffractometer (XRD) for testing. The obtained XRD pattern is shown below. Figure 2 As shown in the figure, the diffraction peaks of the prepared material are consistent with those of the standard card, indicating that antimony selenide was successfully synthesized.

[0034] The obtained Sb2Se3@CMK-3 / PEDOT was placed on a glass slide and compacted flat. Laser Raman spectroscopy was used for testing, with an excitation wavelength of 532 nm and a scanning range of 100–2000 cm⁻¹. - ¹, The test environment was room temperature and atmospheric atmosphere, and the obtained Raman spectrum is as follows. Figure 3 As shown, the Raman spectra of Sb2Se3@CMK-3 coated with PEDOT exhibit the bands (1423 and 1368 cm⁻¹). -1 The results are consistent with the Raman vibrations of PEDOT reported in the literature, indicating the successful polymerization and coating of PEDOT.

[0035] 2. Preparation of lithium-ion secondary batteries 1) Preparation of working electrode sheet for lithium-ion secondary battery: Take 32 mg of the above-prepared Sb2Se3@CMK-3 / PEDOT, 4 mg of acetylene black and 4 mg of polyvinylidene fluoride, grind them in a mortar for 30 min, then add a few drops of N-methylpyrrolidone to make a uniform slurry and coat it on copper foil current collector. After vacuum drying at 110℃ and standing for 12 h, an electrode made of PEDOT-coated Sb2Se3@CMK-3 composite material is obtained. Then cut the prepared electrode into working electrode sheet for lithium-ion secondary battery with a diameter of 12 mm.

[0036] 2) Preparation of lithium-ion secondary battery: Lithium sheet is used as the counter electrode of the working electrode sheet of the lithium-ion secondary battery prepared in step 1), and polypropylene film is used as the separator between the two; the electrolyte is 1 M LiPF6 with 5% FEC added dissolved in EC / DEC solution with a volume ratio of 1:1; the lithium-ion secondary battery (CR2032 type, half cell) is assembled in a glove box filled with argon gas.

[0037] The lithium-ion secondary battery obtained in step 2 was subjected to constant current charge-discharge test within a voltage window of 0.01~2.5 V.

[0038] The first charge-discharge curve at a current density of 0.1 A / g is shown below. Figure 4 As shown, in a lithium-ion half-cell, the electrode fabricated with Sb₂Se₃@CMK-3 / PEDOT achieves an initial discharge specific capacity of 1674 mAh / g and a charge-discharge efficiency of 50.8%. Cycling performance at a current density of 0.5 A / g is as follows... Figure 5As shown, in a lithium-ion half-cell, under a current density of 0.5 A / g, the electrode made of Sb₂Se₃@CMK-3 / PEDOT exhibits a discharge specific capacity of up to 657 mAh / g after 480 cycles. The rate performance of Sb₂Se₃@CMK-3 / PEDOT in lithium-ion batteries is as follows... Figure 6 As shown, the reversible specific capacities of Sb₂Se₃@CMK-3 / PEDOT in the lithium-ion half-cell at current densities of 0.1, 0.2, 0.5, 1.0, and 2.0 A / g are 689, 556, 461, 400, and 357 mAh g, respectively. - ¹ indicates stable cycling and excellent rate performance.

[0039] Example 2 1. Preparation of conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material 1) Add 0.2281 g of antimony trichloride powder to a mixed solvent of 60 mL of deionized water and 10 mL of ethanol, stir for 30 min to obtain an antimony trichloride solution; 2) Accurately weigh 0.1184 g of selenium powder and 0.0851 g of sodium borohydride powder, dissolve them together in 5 mL of deionized water to prepare a transparent NaHSe solution; while stirring, add the transparent NaHSe solution to the antimony trichloride solution, and continue stirring for 20 min to obtain the antimony selenide precursor solution. 3) Add 0.1 g of CMK-5 to the antimony selenide precursor solution obtained in step 2), and continue stirring for 30 min to generate a precursor mixture; 4) The precursor mixture was transferred to a reactor and heated to 180℃ in an oven for 24 h. After being removed, it was naturally cooled to room temperature and centrifuged to collect the black precipitate. The black precipitate was washed 6 times with deionized water and ethanol alternately and then freeze-dried for 12 h to obtain a black powder. The black powder was annealed at 500℃ for 2 h under Ar atmosphere at a rate of 3℃ / min to obtain the Sb2Se3@CMK-5 composite material. 5) Using a pipette, take 17.6 μL of 3,4-ethylenedioxythiophene and add it to 40 mL of 0.1 M hydrochloric acid. Stir vigorously at room temperature for 0.5 h to obtain a mixed solution of EDOT and hydrochloric acid. 6) Take 75 mg of the Sb2Se3@CMK-5 composite material prepared in step 4) and 37.5 mg of ammonium persulfate, add them to the mixed solution of EDOT and hydrochloric acid obtained in step 5), and stir at room temperature for 10 h; filter the stirred sample, wash it with deionized water and anhydrous ethanol, and finally dry it in a vacuum drying oven at 80℃ for 12 h to obtain the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material (Sb2Se3@CMK-5 / PEDOT).

[0040] 2. Preparation of working electrode sheets for lithium-ion secondary batteries Take 32 mg of the Sb2Se3@CMK-5 / PEDOT, 4 mg of acetylene black and 4 mg of PVDF prepared above, grind them in a mortar for 30 min, then add a few drops of N-methylpyrrolidone to make a uniform slurry and coat it on a copper foil current collector. After vacuum drying at 110℃ and standing for 12 h, an electrode made of PEDOT-coated Sb2Se3@CMK-5 composite material is obtained. Then cut the prepared electrode into an electrode sheet with a diameter of 12 mm.

[0041] Example 3 1. Preparation of conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material 1) Add 0.2258 g of antimony trichloride powder to a mixed solvent of 60 mL of deionized water and 11 mL of ethanol, and stir for 30 min to obtain an antimony trichloride solution; 2) Accurately weigh 0.1302 g of selenium powder and 0.1 g of sodium borohydride powder, and dissolve them together in 6.05 mL of deionized water to prepare a transparent NaHSe solution; while stirring, add the transparent NaHSe solution to the antimony trichloride solution, and continue stirring for 20 min to obtain the antimony selenide precursor solution. 3) Add 0.107 g of nitrogen-doped CMK-3 (N-CMK-3) to the antimony selenide precursor solution obtained in step 2), and continue stirring for 40 min to generate a precursor mixture; 4) The precursor mixture obtained in step 3) was transferred to a reaction vessel and heated to 180℃ in an oven for 24 hours. After being removed, it was naturally cooled to room temperature and centrifuged to collect the black precipitate. The black precipitate was washed 6 times with deionized water and ethanol alternately and then freeze-dried for 12 hours to obtain a black powder. The black powder was annealed at 500℃ for 2 hours under Ar atmosphere at a rate of 3℃ / min to obtain the Sb2Se3@N-CMK-3 composite material. 5) Using a pipette, take 17.4 μL of 3,4-ethylenedioxythiophene and add it to 40 mL of 0.1 M hydrochloric acid. Stir vigorously at room temperature for 0.5 h to obtain a mixed solution of EDOT and hydrochloric acid. 6) Take 75 mg of the Sb2Se3@N-CMK-3 composite material prepared in step 4) and 41.3 mg of ammonium persulfate, add them to the mixed solution of EDOT and hydrochloric acid obtained in step 5), and stir at room temperature for 10 h; filter the stirred sample and wash it with deionized water and anhydrous ethanol, and finally dry it in a vacuum drying oven at 80 °C for 12 h to obtain the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material (Sb2Se3@N-CMK-3 / PEDOT).

[0042] 2. Preparation of working electrode sheets for lithium-ion secondary batteries Take 32 mg of the Sb2Se3@N-CMK-3 / PEDOT, 4 mg of acetylene black and 4 mg of PVDF prepared above, grind them in a mortar for 30 min, then add a few drops of N-methylpyrrolidone to make a uniform slurry and coat it on a copper foil current collector. After vacuum drying at 110℃ and standing for 12 h, an electrode made of PEDOT-coated Sb2Se3@N-CMK-3 composite material is obtained. Then cut the prepared electrode into an electrode sheet with a diameter of 12 mm.

[0043] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material, characterized in that, Includes the following steps: 1) Add ordered mesoporous carbon to antimony selenide precursor solution and mix well to obtain precursor mixture; 2) The precursor mixture was kept at 180℃ for 24 h, cooled to room temperature, centrifuged to collect the precipitate, washed, freeze-dried, and annealed at a heating rate of 3℃ / min to 500℃ under an inert atmosphere to obtain the Sb2Se3@OMC composite material. 3) Add ammonium persulfate and Sb2Se3@OMC composite material to a mixed solution of 3,4-ethylenedioxythiophene and dilute hydrochloric acid, mix well, and dry to obtain conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material.

2. The method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material according to claim 1, characterized in that, In step 1), the ordered porous carbon is CMK-3, CMK-5, or a nitrogen-doped derivative thereof.

3. The method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material according to claim 1, characterized in that, In step 1), the preparation method of antimony selenide precursor solution is as follows: add antimony trichloride powder to a mixed solution of deionized water and ethanol and mix well to obtain antimony trichloride solution; dissolve selenium powder and sodium borohydride powder in deionized water to obtain NaHSe solution; under stirring, add NaHSe solution to antimony trichloride solution and mix well to obtain antimony selenide precursor solution.

4. The method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material according to claim 3, characterized in that, The total mass ratio of antimony trichloride to selenium in the ordered mesoporous carbon and antimony selenide precursor solution was (1.9~2.1):7.

0.

5. The method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material according to claim 3, characterized in that, The molar ratio of selenium powder to sodium borohydride powder is (2.9~3.1):5.0; the volume ratio of ethanol in antimony trichloride solution to deionized water in NaHSe solution is 2.0:(0.9~1.1); the molar ratio of antimony trichloride in antimony trichloride solution to selenium in antimony selenide precursor solution is (0.9~1.1):1.

5.

6. A method for preparing a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material according to any one of claims 1 to 4, characterized in that, In step 2), the mass ratio of Sb2Se3@OMC composite material to ammonium persulfate is 2.0:(0.9~1.1), and the molar ratio of 3,4-ethylenedioxythiophene to ammonium persulfate is (0.9~1.1):1.

0.

7. The conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material according to claim 7 in the preparation of lithium-ion batteries.

9. A working electrode sheet for a lithium-ion secondary battery, characterized in that, The present invention includes a current collector and an active material coating coated on the current collector, wherein the active material coating contains a conductive polymer-coated antimony selenide / ordered mesoporous carbon composite anode material prepared by any one of claims 1 to 6.

10. A lithium-ion secondary battery, characterized in that, It is assembled from a counter electrode, a separator, an electrolyte, and the working electrode sheet of the lithium-ion secondary battery as described in claim 9.

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