Method for induced synthesis of SnS2 / C composite material by taking eggshell membrane as biological template
By using eggshell membrane as a biological template to prepare SnS2/C composite materials, the problems of volume expansion and weak interfacial bonding of SnS2 anode materials in lithium-ion batteries are solved, achieving high-efficiency electrochemical performance and structural stability, making it suitable for lithium-ion battery anode materials.
Patent Information
- Application Number
- CN202511731471.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-02-17
AI Technical Summary
Existing SnS2 anode materials in lithium-ion batteries suffer from problems such as large volume expansion, poor conductivity, and easy pulverization and shedding of active materials, resulting in poor cycle stability and low rate performance. Furthermore, traditional composite methods are difficult to achieve uniform dispersion and weak interfacial bonding.
Using eggshell membrane as a biological template, Sn2+ is uniformly dispersed through electrostatic adsorption and coordination. Combined with hydrothermal sulfidation and low-temperature carbonization, a SnS2/C composite structure is formed. The in-situ growth of SnS2 nanoneedles is enhanced at the interface by CVD, thereby improving the interfacial bonding force.
Uniform anchoring and structural stability of SnS2/C composite materials at the nanoscale were achieved, significantly improving the cycle stability and rate performance of the battery, as well as increasing the battery's capacity retention and charge/discharge efficiency.
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Figure CN121546026A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium-ion battery materials technology, specifically to a method for inducing the synthesis of SnS2 / C composite materials using eggshell membrane as a biological template and its application. Background Technology
[0002] With the rapid development of new energy vehicles, portable electronic devices, and energy storage systems, higher demands are being placed on the energy density, cycle life, and safety of lithium-ion batteries. As a core component of lithium-ion batteries, the performance of the anode material directly affects the overall battery performance. Currently, the theoretical specific capacity of commercially available graphite anodes is only 372 mAh / g, which is insufficient to meet the needs of high-energy-density batteries. Therefore, developing novel anode materials with high capacity and long lifespan has become a research hotspot.
[0003] Tin-based sulfides (such as SnS2) are considered to be among the most promising anode materials due to their high theoretical specific capacity (approximately 1137 mAh / g), abundant natural resources, and moderate lithium intercalation potential. However, SnS2 suffers from problems such as large volume expansion (approximately 250%), poor conductivity, and easy pulverization and shedding of active materials during charge and discharge, resulting in poor cycle stability and low rate performance, which severely limits its practical applications.
[0004] To alleviate these problems, researchers often combine SnS2 with carbon materials, utilizing carbon's high conductivity and buffering effect to improve the material's structural stability. However, traditional composite methods (such as mechanical mixing and hydrothermal synthesis) struggle to achieve uniform dispersion of SnS2 in a carbon matrix, and the interfacial bonding is weak, making it prone to active material stripping after long-term cycling. Furthermore, existing synthetic routes often employ toxic reagents or high-temperature, high-pressure conditions, resulting in high costs and significant environmental impact. Summary of the Invention
[0005] The purpose of this invention is to provide a method for inducing the synthesis of SnS2 / C composite materials using eggshell membrane as a biological template. This method is simple, low-cost, and environmentally friendly, and the resulting composite material has excellent electrochemical properties, making it suitable for lithium-ion battery anode materials.
[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for inducing the synthesis of SnS2 / C composite materials using eggshell membrane as a biological template includes the following steps: S1. Eggshell membrane pretreatment Clean the eggshells to remove impurities, then soak them in HCl solution and separate the eggshell membrane. Wash the eggshell membrane (ESM) with deionized water and then dry them for later use. S2. Preparation of precursors by adsorption reaction Eggshell membrane was prepared into a dispersion, SnCl2 and thioacetamide were added, and then a hydrothermal reaction was carried out. After centrifugation, a precipitate was obtained. The precipitate was washed with deionized water and ethanol and dried to obtain the SnS2 / ESM precursor. S3. Inert atmosphere carbonization The SnS2 / ESM precursor was carbonized under inert gas at 320-380℃ to obtain the SnS2 / C composite material.
[0007] Preferably, the preparation method of the present invention further includes interface enhancement treatment, the specific steps of which are: S4. Interface Enhancement Processing SnS2 nanoneedles were grown in situ on the surface of SnS2 / C composite material using CVD. In a dual-temperature zone tube furnace, the SnS2 / C composite material prepared by S3 was placed in the low-temperature zone, while sulfur powder and SnO2 nanoparticles were placed in the high-temperature zone. Under argon protection, the temperature was increased to 500-550℃ and 600-650℃ respectively at a heating rate of 10-15℃ / min, and held for 1.5-2.5h. Then, the temperature was naturally cooled to room temperature to obtain the interface-reinforced SnS2 / C composite material.
[0008] Preferably, the method for preparing the eggshell membrane into a dispersion in step S2 is as follows: After cutting the eggshell membrane into small pieces, place it in deionized water and ultrasonically disperse for 30-60 minutes to obtain a uniform dispersion. Among them, the eggshell membrane is cut into pieces of 1-4mm. 2 The fragments are ultrasonically dispersed at a power of 200-400W; the concentration of eggshell membrane in the dispersion is 5-15mg / mL; the concentration of SnCl2 solution is 0.05-0.15mol / L; and the molar ratio of thioacetamide to SnCl2 is 1-2:1.
[0009] Preferably, in step S2, citric acid is added before the hydrothermal reaction. The specific operation method is as follows: Add citric acid and SnCl2 to the dispersion, stir at 60℃ for 1-2 hours, then add thioacetamide and continue stirring for 15-30 minutes until dissolved; the molar ratio of citric acid to SnCl2 is 1:1-1:2.
[0010] Preferably, in step S2, the eggshell membrane dispersion is mixed with SnCl2 and thioacetamide and then transferred to a polytetrafluoroethylene liner, placed in a hydrothermal reactor, heated to 160-180°C and kept at that temperature for 10-14 hours, and then cooled to room temperature after the reaction is completed.
[0011] Preferably, the inert gas in step S3 is nitrogen or argon, the carbonization heating rate is 2-5℃ / min, and the holding time is 2-4h.
[0012] The advantages of this invention are: 1. This invention uses the eggshell membrane as a biological template, and utilizes electrostatic adsorption and coordination to enable Sn... 2+ Uniformly dispersed on the surface of protein fibers, SnS2 / C composite structures are formed through hydrothermal sulfidation and low-temperature carbonization. The three-dimensional network of the eggshell membrane is transformed into a nitrogen / sulfur co-doped conductive carbon framework after carbonization, which not only provides a continuous electronic pathway but also buffers the volume expansion during SnS2 lithium intercalation, achieving uniform anchoring and structural stability of the active material at the nanoscale.
[0013] 2. In this invention, citric acid is introduced during the hydrothermal stage, reacting with Sn. 2+ This process forms stable complexes, inhibits premature hydrolysis, and thus regulates the nucleation rate of SnS2, improving the interfacial bonding between the active material and biochar. Simultaneously, this invention employs vapor deposition to perform secondary growth on the SnS2 / C composite material, anchoring SnS2 nanoneedles in situ to the carbon matrix, enhancing interfacial bonding energy and effectively suppressing the stripping and pulverization of the active material during cycling.
[0014] 3. The SnS2 / C composite material prepared by this invention has excellent electrochemical performance and can be used as a negative electrode material for lithium-ion batteries to improve the cycle stability and rate performance of the battery, and significantly improve the capacity retention and charge / discharge efficiency of the battery. Attached Figure Description
[0015] Figure 1 The image shown is a SEM image of the sample prepared in Example 1.
[0016] Figure 2 The image shows a SEM image of the sample prepared in Example 2.
[0017] Figure 3 The image shown is a SEM image of the sample prepared in Example 3. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0019] Example 1 This embodiment discloses a method for inducing the synthesis of SnS2 / C composite materials using eggshell membrane as a biological template, comprising the following steps: S1. Eggshell membrane pretreatment Collect fresh eggshells, crack them to remove residual egg white, and rinse the surface stains three times with deionized water; put the treated eggshells into a beaker, add 2 mol / L hydrochloric acid solution, ensuring that the solution completely submerges the eggshells, with a liquid-to-solid ratio of 5:1 (mL:g), seal and soak at room temperature for 12 hours, stirring gently once every 3 hours during this period; Remove the soaked eggshell membrane with tweezers and wash it repeatedly in deionized water. After each wash, measure the pH of the washing solution with a pH meter until the pH reaches 6.8. The purified eggshell membrane was spread evenly in a petri dish and placed in a vacuum drying oven. It was dried at 60°C and 40Pa for 12 hours. After drying, it was sealed and stored in a desiccator for later use.
[0020] S2. Preparation of precursors by adsorption reaction Cut the eggshell membrane into 1-4mm pieces. 2 Weigh 1.000g of eggshell membrane fragments and place them in a 50mL beaker. Add 20mL of deionized water and place the beaker in an ultrasonic cleaner (300W, 25℃) for ultrasonic dispersion for 30min to form a uniform dispersion. Place the beaker on a magnetic stirrer and stir at 300 r / min. Slowly add 0.01 mol of SnCl2 and continue stirring for 1 h. Then add 0.015 mol of thioacetamide and continue stirring for 30 min to obtain a pale yellow mixture. Slowly pour the mixture into a 50mL polytetrafluoroethylene liner, ensuring no air bubbles remain. Place the liner into a stainless steel hydrothermal reactor and tighten the lid to initiate the hydrothermal reaction. Place the hydrothermal reactor into a digital display constant temperature water bath, set the heating rate to 5℃ / min, and maintain the temperature at 180℃ for 12 hours. Monitor the temperature in real time during this period to ensure that the fluctuation does not exceed ±0.5℃. After the reaction is complete, turn off the water bath and allow it to cool naturally to room temperature. The mixture in the liner was transferred to a centrifuge tube, 10 mL of deionized water was added, and the tube was centrifuged at 8000 r / min for 10 min in a high-speed centrifuge. The supernatant was discarded. This operation was repeated 3 times. Then, anhydrous ethanol was used to replace the deionized water, and the tube was centrifuged and washed 3 times. The black powder after centrifugation was transferred to a vacuum drying oven and dried at 80℃ and 10 Pa for 12 h to obtain the SnS2 / ESM precursor, which was then sealed and stored.
[0021] S3. Inert atmosphere carbonization Weigh 0.5g of SnS2 / ESM precursor powder and spread it evenly in an alumina boat. Place the boat in the middle of the quartz tube of a tubular furnace. Open the argon valve and adjust the flow rate to 50mL / min. Continuously purge the air from the quartz tube with argon for 30min. Set the tubular furnace heating program to heat to 350℃ at a rate of 10℃ / min and hold for 2h. After the holding period, continue to purge with argon and allow it to cool naturally to room temperature. Remove the boat to obtain black SnS2 / C composite powder.
[0022] Example 2 This embodiment discloses a method for inducing the synthesis of SnS2 / C composite materials using eggshell membrane as a biological template, comprising the following steps: S1. Eggshell membrane pretreatment Collect fresh eggshells, crack them to remove residual egg white, and rinse the surface stains three times with deionized water; put the treated eggshells into a beaker, add 2 mol / L hydrochloric acid solution, ensuring that the solution completely submerges the eggshells, with a liquid-to-solid ratio of 5:1 (mL:g), seal and soak at room temperature for 12 hours, stirring gently once every 3 hours during this period; Remove the soaked eggshell membrane with tweezers and wash it repeatedly in deionized water. After each wash, measure the pH of the washing solution with a pH meter until the pH reaches 6.8. The purified eggshell membrane was spread evenly in a petri dish and placed in a vacuum drying oven. It was dried at 60°C and 40Pa for 12 hours. After drying, it was sealed and stored in a desiccator for later use.
[0023] S2. Preparation of precursors by adsorption reaction Cut the eggshell membrane into 1-4mm pieces. 2 Weigh 1.000g of eggshell membrane fragments and place them in a 50mL beaker. Add 20mL of deionized water and place the beaker in an ultrasonic cleaner (300W, 25℃) for ultrasonic dispersion for 30min to form a uniform dispersion. Place the beaker on a magnetic stirrer and stir at 300 r / min. Slowly add 0.01 mol SnCl2 and 0.01 mol citric acid and continue stirring for 1 h. Then add 0.015 mol thioacetamide and continue stirring for 30 min to obtain a pale yellow mixture. Slowly pour the mixture into a 50mL polytetrafluoroethylene liner, ensuring no air bubbles remain. Place the liner into a stainless steel hydrothermal reactor and tighten the lid to initiate the hydrothermal reaction. Place the hydrothermal reactor into a digital display constant temperature water bath, set the heating rate to 5℃ / min, and maintain the temperature at 180℃ for 12 hours. Monitor the temperature in real time during this period to ensure that the fluctuation does not exceed ±0.5℃. After the reaction is complete, turn off the water bath and allow it to cool naturally to room temperature. The mixture in the liner was transferred to a centrifuge tube, 10 mL of deionized water was added, and the tube was centrifuged at 8000 r / min for 10 min in a high-speed centrifuge. The supernatant was discarded. This operation was repeated 3 times. Then, anhydrous ethanol was used to replace the deionized water, and the tube was centrifuged and washed 3 times. The black powder after centrifugation was transferred to a vacuum drying oven and dried at 80℃ and 10 Pa for 12 h to obtain the SnS2 / ESM precursor, which was then sealed and stored.
[0024] S3. Inert atmosphere carbonization Weigh 0.5g of SnS2 / ESM precursor powder and spread it evenly in an alumina boat. Place the boat in the middle of the quartz tube of a tubular furnace. Open the argon valve and adjust the flow rate to 50mL / min. Continuously purge the air from the quartz tube with argon for 30min. Set the tubular furnace heating program to heat to 350℃ at a rate of 10℃ / min and hold for 2h. After the holding period, continue to purge with argon and allow it to cool naturally to room temperature. Remove the boat to obtain black SnS2 / C composite powder.
[0025] Unlike Example 1, in this example, citric acid is added before the hydrothermal reaction in step S2, with a molar ratio of citric acid to SnCl2 of 1:1. Citric acid acts as a complexing agent and can react with SnCl2. 2+ Forming stable complexes to avoid Sn 2+ Pre-hydrolysis generates stannous hydroxide precipitate, while simultaneously enhancing Sn. 2+ The selective adsorption of SnS2 on the eggshell membrane surface improves the uniform loading of SnS2 on the eggshell membrane fibers and the binding effect with the eggshell membrane fibers.
[0026] Example 3 This embodiment discloses a method for inducing the synthesis of SnS2 / C composite materials using eggshell membrane as a biological template, comprising the following steps: S1. Eggshell membrane pretreatment Collect fresh eggshells, crack them to remove residual egg white, and rinse the surface stains three times with deionized water; put the treated eggshells into a beaker, add 2 mol / L hydrochloric acid solution, ensuring that the solution completely submerges the eggshells, with a liquid-to-solid ratio of 5:1 (mL:g), seal and soak at room temperature for 12 hours, stirring gently once every 3 hours during this period; Remove the soaked eggshell membrane with tweezers and wash it repeatedly in deionized water. After each wash, measure the pH of the washing solution with a pH meter until the pH reaches 6.8. The purified eggshell membrane was spread evenly in a petri dish and placed in a vacuum drying oven. It was dried at 60°C and 40Pa for 12 hours. After drying, it was sealed and stored in a desiccator for later use.
[0027] S2. Preparation of precursors by adsorption reaction Cut the eggshell membrane into 1-4mm pieces. 2Weigh 1.000g of eggshell membrane fragments and place them in a 50mL beaker. Add 20mL of deionized water and place the beaker in an ultrasonic cleaner (300W, 25℃) for ultrasonic dispersion for 30min to form a uniform dispersion. Place the beaker on a magnetic stirrer and stir at 300 r / min. Slowly add 0.01 mol SnCl2 and 0.01 mol citric acid and continue stirring for 1 h. Then add 0.015 mol thioacetamide and continue stirring for 30 min to obtain a pale yellow mixture. Slowly pour the mixture into a 50mL polytetrafluoroethylene liner, ensuring no air bubbles remain. Place the liner into a stainless steel hydrothermal reactor and tighten the lid to initiate the hydrothermal reaction. Place the hydrothermal reactor into a digital display constant temperature water bath, set the heating rate to 5℃ / min, and maintain the temperature at 180℃ for 12 hours. Monitor the temperature in real time during this period to ensure that the fluctuation does not exceed ±0.5℃. After the reaction is complete, turn off the water bath and allow it to cool naturally to room temperature. The mixture in the liner was transferred to a centrifuge tube, 10 mL of deionized water was added, and the tube was centrifuged at 8000 r / min for 10 min in a high-speed centrifuge. The supernatant was discarded. This operation was repeated 3 times. Then, anhydrous ethanol was used to replace the deionized water, and the tube was centrifuged and washed 3 times. The black powder after centrifugation was transferred to a vacuum drying oven and dried at 80℃ and 10 Pa for 12 h to obtain the SnS2 / ESM precursor, which was then sealed and stored.
[0028] S3. Inert atmosphere carbonization Weigh 0.5g of SnS2 / ESM precursor powder and spread it evenly in an alumina boat. Place the boat in the middle of the quartz tube of a tubular furnace. Open the argon valve and adjust the flow rate to 50mL / min. Continuously purge the air from the quartz tube with argon for 30min. Set the tubular furnace heating program to heat to 350℃ at a rate of 10℃ / min and hold for 2h. After the holding period, continue to purge with argon and allow it to cool naturally to room temperature. Remove the boat to obtain black SnS2 / C composite powder.
[0029] S4. Interface Enhancement Processing The SnS2 / C composite material prepared by S3 was placed in a low-temperature region, while sulfur powder and SnO2 nanoparticles were placed in a high-temperature region. Under argon protection, the temperature was increased to 500-550℃ and 600-650℃ respectively at a heating rate of 10-15℃ / min, and held for 1.5-2.5h. Then, it was naturally cooled to room temperature to obtain the interface-reinforced SnS2 / C composite material.
[0030] In this embodiment, SnS2 is generated by the gas-phase reaction of SnO2 and S2 in the high-temperature region. Driven by the temperature gradient, SnS2 migrates to the surface of the SnS2 / C composite material in the low-temperature region. On the one hand, it fills the interfacial gaps of the SnS2 / C composite material, and on the other hand, it forms an anchoring structure through chemical bonding, which enhances the interfacial force between SnS2 and carbon and reduces the risk of active material peeling off during charging and discharging.
[0031] The present invention characterized Examples 1, 2 and 3 respectively, and observed the microstructure of the obtained samples by scanning electron microscopy (SEM).
[0032] Scanning electron microscopy (SEM): Accelerating voltage 10kV, the microstructure of the material was observed, the average particle size and dispersion uniformity of SnS2 particles were statistically analyzed, and the interfacial gap filling conditions of each group were compared. Results are as follows: Figure 1-3 As shown, in Example 1, the average particle size of SnS2 particles is 240 nm, and the dispersion is relatively uniform, but there is a small amount of agglomeration, and the interfacial gaps are not completely filled; in Example 2, the average particle size is about 180 nm, the distribution is more uniform, but there is also a small amount of agglomeration, and the interfacial bonding is relatively tight; in Example 3, the average particle size is about 165 nm, the dispersion is high, the interfacial bonding is dense, there is almost no agglomeration, and a continuous "anchoring knot" is formed between SnS2 and the carbon matrix, which significantly improves the structural stability of the composite material.
[0033] Comparing Example 2 with Example 1, it is shown that adding citric acid can effectively regulate the nucleation and growth process of SnS2, improve interfacial bonding, and enhance dispersibility. Comparing Example 3 with Example 2 further demonstrates that secondary reinforcement of the bonding interface using CVD vapor deposition can significantly promote the chemical bonding between SnS2 and the carbon matrix, transforming the interfacial contact from physical adsorption to covalent bonding, thereby greatly improving the structural integrity of the composite material.
[0034] The present invention also tested the electrochemical performance of the prepared SnS2 / C composite material. A control group and the SnS2 / C composite materials prepared in Examples 1-3 were used as active materials to prepare lithium-ion battery anodes. The control group used commercial SnS2 powder (purity ≥99.9%, particle size approximately 100-200 nm).
[0035] The preparation method involves mixing the active material, conductive agent (Super P), and binder (PVDF) in a mass ratio of 8:1:1, dissolving them in N-methylpyrrolidone to form a uniform slurry, coating it onto copper foil, drying it, and then cutting it into pieces to serve as the working electrode.
[0036] Electrochemical testing conditions: 1. Cyclic voltammetry test: scan rate of 0.1 mV / s, voltage window of 0.01–3.0 V (vs. Li⁺ / Li), performed on a CHI760E electrochemical workstation.
[0037] 2. Constant current charge-discharge test: conducted on the LANDT battery testing system, with a current density of 0.1 A / g, a voltage range of 0.01–3.0 V (vs. Li⁺ / Li), and 100 cycles.
[0038] 3. Rate performance test: Test sequentially at current densities of 100, 200, 500, 1000, and 2000 mA / g, with 10 cycles per cycle, and record the specific capacity change.
[0039] 4. AC impedance test: Performed on a CHI760E electrochemical workstation, with a frequency range of 100 kHz–0.01 Hz, a perturbation voltage of 5 mV, and a test temperature of 25℃.
[0040] The test results are shown in the table below: Table 1: Comparison of first-cycle charge-discharge performance (current density: 100 mA / g) Group First discharge capacity (mAh / g) First charge capacity (mAh / g) First-lap coulomb efficiency (%) control group 1125 680 60.4% Example 1 1280 850 66.4% Example 2 1350 950 70.4% Example 3 1450 1100 75.9% Table 2: Cyclic performance comparison (current density: 500 mA / g, 100 cycles) Group Second cycle capacity (mAh / g) Capacity at 100th cycle (mAh / g) Capacity retention rate (%) control group 650 320 49.2% Example 1 820 520 63.4% Example 2 900 680 75.6% Example 3 1050 890 84.8% Table 3: Rate Performance Comparison (Capacity at 10th Cycle, mAh / g) Group 100 mA / g 200 mA / g 500 mA / g 1000 mA / g 2000 mA / g Returns 100 mA / g control group 650 520 380 250 150 580 Example 1 820 750 680 580 450 780 Example 2 900 850 780 700 580 860 Example 3 1050 980 920 850 750 1000 Table 4: AC impedance fitting results (Rs: solution resistance, Rct: charge transfer resistance) Group Rs (Ω) Rct (Ω) control group 2.8 185 Example 1 2.5 120 Example 2 2.3 85 Example 3 2.1 45 As shown in Table 1, the first-cycle discharge capacity and coulombic efficiency of Example 3 were significantly higher than those of the other groups, indicating that it had higher utilization of active materials and better reversibility of lithium-ion insertion / extraction. Combined with Table 2, Example 3 maintained 84.8% capacity retention after 100 cycles, far superior to the 49.2% of the control group, demonstrating a significant improvement in cycle stability of the battery prepared using Example 3.
[0041] As shown in Table 3, Example 3 exhibits a significant capacity advantage at high rates, reaching 750 mAh / g even at 2000 mA / g. Furthermore, the capacity almost fully recovers after restoring to a low current density, indicating that Example 3 has excellent rate adaptability. In Table 4, the Rct value decreased from 185 Ω in the control group to 45 Ω in Example 3, demonstrating that CVD treatment can effectively enhance the kinetic performance of the electrode interface, significantly reduce charge transfer impedance, and improve the lithium-ion transport rate.
[0042] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A method for inducing synthesis of SnS2 / C composite material with eggshell membrane as a biomtemplate, characterized in that, The method comprises the following steps: S1. Eggshell membrane pretreatment The eggshell is cleaned to remove impurities, then soaked in an HCl solution, and the eggshell membrane is separated, the eggshell membrane (ESM) is washed with deionized water, and then dried for use; S2. Preparation of precursor by adsorption reaction The eggshell membrane is prepared into a dispersion liquid, SnCl2 and thioacetamide are added, then a hydrothermal reaction is performed, the precipitate is separated by centrifugation, and the precipitate is washed with deionized water and ethanol, and then dried to obtain a SnS2 / ESM precursor; S3. Carbonization in inert atmosphere The SnS2 / ESM precursor is carbonized at 320-380℃ under the protection of an inert gas to obtain a SnS2 / C composite material.
2. The method according to claim 1, wherein the method for inducing synthesis of SnS2 / C composite material by using eggshell membrane as a biomatrix is characterized in that, The method further comprises an interface enhancement treatment, and the specific steps are as follows: S4. Interface enhancement treatment SnS2 nanoneedles are in-situ grown on the surface of the SnS2 / C composite material by using a CVD method, the SnS2 / C composite material prepared in S3 is placed in a low-temperature zone in a double-temperature-zone tube furnace, sulfur powder and SnO2 nanoparticles are placed in a high-temperature zone, the temperature is raised to 500-550℃ and 600-650℃ at a temperature raising rate of 10-15℃ / min under the protection of argon, and then kept for 1.5-2.5h, and then naturally cooled to room temperature to obtain an interface-enhanced SnS2 / C composite material.
3. The method according to claim 2, wherein the method for inducing synthesis of SnS2 / C composite material by using eggshell membrane as a biomatrix is characterized in that, The flow rate of the argon is 100-150sccm.
4. The method according to claim 1, wherein the method for inducing synthesis of SnS2 / C composite material by using eggshell membrane as a biomatrix is characterized in that, The method for preparing the eggshell membrane into a dispersion liquid in S2 is as follows: The eggshell membrane is cut into pieces, then placed in deionized water, and ultrasonically dispersed for 30-60min to obtain a uniform dispersion liquid; Among them, the eggshell membrane is cut into pieces of 1-4mm. 2 The fragments were ultrasonically dispersed at a power of 200-400W; the concentration of SnCl2 was 0.05-0.15mol / L; and the molar ratio of thioacetamide to SnCl2 was 1-2:
1.
5. The method for inducing synthesis of SnS2 / C composite material with eggshell membrane as biomimetic template according to claim 4, characterized in that, Before the hydrothermal reaction in S2, citric acid is further added, and the specific operation method is as follows: Citric acid and SnCl2 are added to the dispersion liquid, constant temperature stirring is performed at 60℃ for 1-2h, then thioacetamide is added, and stirring is continued for 15-30min until dissolution; the molar ratio of the citric acid to SnCl2 is 1:1-1:
2.
6. The method according to claim 1, wherein the method for inducing synthesis of SnS2 / C composite material by using eggshell membrane as a biomatrix is characterized in that, After the dispersion liquid of the eggshell membrane is mixed with SnCl2 and thioacetamide, it is transferred to a polytetrafluoroethylene liner, and placed in a hydrothermal kettle, heated to 160-180℃ and kept for 10-14h, and then cooled to room temperature after the reaction is completed.
7. The method according to claim 1, wherein the method for inducing synthesis of SnS2 / C composite material by using eggshell membrane as a biomatrix is characterized in that, In S3, the inert gas is nitrogen or argon, the carbonization temperature raising rate is 2-5℃ / min, and the holding time is 2-4h.
8. The SnS2 / C composite material prepared by the method of any one of claims 1-7.
9. The application of the SnS2 / C composite material of claim 8 in the preparation of a lithium ion battery negative electrode material.