Preparation method of mesoporous silica nanosphere composite material and application of mesoporous silica nanosphere composite material as lithium ion battery negative electrode material
Nitrogen-doped SiO2@C composite materials were prepared by amidation reaction, which solved the problem of limited cycle life of SiO2 anode materials in lithium-ion batteries due to volume changes, and achieved high-efficiency electrochemical performance improvement and commercialization potential.
Patent Information
- Application Number
- CN202410547362.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-08
- Publication Date
- 2026-01-09
AI Technical Summary
The existing lithium-ion battery anode material SiO2 has a limited cycle life and deteriorates electrochemical performance due to volume changes during lithium insertion/deintercalation, making it difficult to achieve large-scale commercialization of composite strategies.
Nitrogen-doped SiO2@C composite materials were prepared by amidation reaction. A two-dimensional sheet structure was formed by the self-assembly of mesoporous SiO2 nanospheres and carbon sheets. Using carboxylic acid and nitrogen-containing heterocyclic organic compounds as dual carbon sources, uniform anchoring and nitrogen doping of SiO2 nanospheres were achieved.
It effectively mitigates the volume change of SiO2 during charging and discharging, maintains the active surface and ion transport channels, and improves electrochemical performance and coulombic efficiency, making it suitable for commercial production.
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Figure CN121306971A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of preparation of lithium ion battery negative electrode materials, and particularly relates to a preparation method of mesoporous silica nanosphere composite material and application of the mesoporous silica nanosphere composite material as a lithium ion battery negative electrode material. BACKGROUND
[0002] Graphite-based materials are the most widely used negative electrode of lithium ion batteries to date. After decades of development and optimization, the actual development capacity has approached the theoretical capacity, which cannot meet the actual needs of high-energy-density lithium ion batteries. In addition, the world's energy structure is transforming towards green and low carbon, so it is urgent to develop new and efficient negative electrode materials for lithium ion batteries. SiO2 has become one of the most potential negative electrode materials due to its ultra-high theoretical capacity. However, the limited cycle life due to the severe volume change during the lithium intercalation / deintercalation process hinders its practical application. Moreover, during repeated cycles, SiO2 particles are pulverized, the unstable solid electrolyte interface (SEI) film is repeatedly broken and formed, and the active material is detached, leading to a sharp deterioration of the electrochemical performance.
[0003] At present, the modification of SiO2 negative electrode materials is relatively extensive, which can be roughly divided into two categories: nanocrystallization and compounding. Since the conductivity of SiO2 material itself is extremely poor, heteroatom-doped carbon-based materials are widely used to enhance the conductivity. Nitrogen doping can adjust the band gap, introduce defects to the matrix material, and provide more active sites to adsorb Li + . The introduction of nitrogen atoms can effectively increase the interlayer spacing of carbon atoms, which can significantly promote the intercalation and deintercalation of Li + . Moreover, pyrrole N-doping helps to improve the reversible charge capacity due to its large adsorption energy and low penetration energy barrier for Li + . It is worth noting that graphene and MXene materials exhibit unique charm. The two-dimensional sheet structure composed of carbon atoms can avoid aggregation or accumulation during charging and discharging, thereby maintaining the initial active surface and open ion transmission channel.
[0004] Many feasible strategies have been explored to produce graphene and graphenelike materials, including chemical vapor deposition, chemical and electrochemical exfoliation, etc. Among them, the graphene prepared by gas deposition and electrochemical exfoliation is the most perfect, but the complex synthesis process and technical barriers seriously hinder its large-scale commercialization. Relatively speaking, the preparation of graphenelike two-dimensional structure by chemical method is most promising for large-scale production. This method not only has the scalability required for commercialization, but also has great flexibility in adjusting the chemical structure of two-dimensional materials. However, the compounding process of graphenelike structure and SiO2 material still lacks exploration, and the most commonly used strategies are mechanical mixing, ultrasonic atomization, electrostatic adsorption and gas phase deposition, etc. How to cleverly compound the two still faces great challenges. SUMMARY
[0005] The application aims to provide a relatively simple preparation process, which utilizes an amidation reaction to prepare a two-dimensional structure of graphene-like, and anchors mesoporous SiO2 nanospheres in the carbon sheet to obtain a nitrogen-doped SiO2@C composite material. The material is used as a negative electrode of a lithium ion battery to improve the deterioration of the electrochemical performance of SiO2 material in the charging and discharging process.
[0006] To achieve the above-mentioned purpose, the application adopts the following technical solutions: A preparation method of mesoporous silica nanosphere composite material, the preparation method comprises the following steps: 1) A certain amount of silane coupling agent and silicon source is added dropwise into an aqueous solution containing a cationic surfactant to obtain a reaction solution, and after the liquid phase reaction is completed, the amino-functionalized mesoporous SiO2 nanospheres are prepared after being filtered, acid washed and dried; 2) The obtained mesoporous SiO2 nanospheres are ultrasonically dispersed in a carboxylic acid-containing aqueous solution to obtain a dispersion liquid A; 3) An organic compound containing a nitrogen-containing heterocycle is dissolved in water to obtain a solution B; 4) The dispersion liquid A and the solution B are mixed, and after the amidation reaction is completed, the precipitate is obtained after being filtered, washed and dried; The conditions of the above-mentioned amidation reaction are as follows: the reaction temperature is 25-40℃, and the reaction time is 20-35h; 5) The precipitate is subjected to a carbonization reaction under an argon atmosphere to obtain a nitrogen-doped SiO2@C composite material; The carbonization reaction conditions are as follows: the reaction temperature is 700-900℃, and the reaction time is 1.5-4h.
[0007] Further, in step 1), the concentration of the silane coupling agent in the reaction solution is 0.03-0.2mol / L; The concentration of the silicon source in the reaction solution is 0.1-0.3mol / L; The concentration of the cationic surfactant in the reaction solution is 0.1-0.3mol / L; The concentration of the acid used for acid washing is 0.5-2mol / L; The liquid phase reaction temperature is 35-50℃, and stirring is accompanied; The product drying process is carried out in an oven at 60-100℃.
[0008] Further, in step 2), the SiO2 nanosphere content in the dispersion liquid A is 2%-10%; The concentration of the carboxylic acid in the dispersion liquid A is 0.3-0.5mol / L.
[0009] Further, the concentration of the nitrogen-containing heterocyclic organic compound in solution B in step 3) is 0.15-0.25 mol / L.
[0010] The amidation reaction in step 4) is accompanied by stirring; The washing agent is deionized water and ethanol, and the drying process is carried out in an oven at 60-100 DEG C.
[0011] Further, the flow rate of the inert gas in step 5) is 50-55 sccm.
[0012] A mesoporous silica nanosphere composite material is prepared according to the preparation method of the present application.
[0013] The present application further provides the application of the mesoporous silica nanosphere composite material as a negative electrode material of a lithium ion battery.
[0014] Compared with the prior art, the present application has the following beneficial effects: The preparation method of the two-dimensional carbon structure anchoring mesoporous SiO2 nanosphere composite material of the present application is different from the general composite methods such as mechanical mixing or gas phase deposition, and uses carboxylic acid and nitrogen-containing heterocyclic organic compound as double carbon sources, utilizes the amino groups grafted on the surface of SiO2 nanospheres and the carboxyl groups of carboxylic acid, and the dehydration condensation reaction between carboxylic acid and nitrogen-containing heterocyclic organic compound, so as to self-assemble into a sheet structure; and a large number of mesoporous SiO2 nanospheres are uniformly anchored on the carbon sheet. The two-dimensional sheet structure can also avoid aggregation or accumulation during charging and discharging, so as to maintain the initial active surface and open ion transmission channel, and effectively alleviate the volume change defect of SiO2 during charging and discharging.
[0015] Further, the amino-functionalized SiO2 nanospheres are prepared by a one-step method, the particle size is uniform, the mesopores are ordered, and the specific surface area is large; and the grafted amino groups and nitrogen-containing heterocyclic organic compounds are used as nitrogen sources for doping, nitrogen doping induces more electron clouds into the carbon matrix, and accelerates electron transfer; the one-step synthesis method of the amino-functionalized SiO2 nanomaterials can also be popularized to the fields of energy, catalysis, adsorption, separation, etc.
[0016] Further, the composite material is prepared by a liquid phase reaction and a heat treatment method, the proportion of nitrogen-doped carbon can be adjusted; the raw material cost required in the whole preparation process is low and easy to obtain, the process is simple, the reaction conditions are mild, the product stability is good, and the product has the scalability and flexibility required for commercialization.
[0017] The two-dimensional carbon structure anchoring mesoporous SiO2 nanosphere composite material of the present application shortens the Li +The transmission interval is large, the specific surface area is large, more active sites are provided, and the electrolyte is beneficial to fully contact with the electrode; nitrogen doping provides more defects for the carbon matrix, accelerates electron transfer; the SiO2 nano material is uniformly distributed, the mesoporous is ordered, is firmly anchored in the two-dimensional carbon sheet, and enhances the lithium storage capacity.
[0018] The application of the two-dimensional carbon structure anchoring mesoporous SiO2 nanosphere composite material as a lithium ion battery negative electrode material, the negative electrode made of the material is subjected to electrochemical test, is charged and discharged at a small current density, and the capacity retention rate can reach more than 97%; the long cycle performance is excellent at a large current density, the stability is good; the rate performance is excellent at different current densities, and the structure is stable; the application of the two-dimensional carbon structure anchoring mesoporous SiO2 nanosphere composite material as a lithium ion battery negative electrode material can significantly improve the 20-30% initial coulomb efficiency of the SiO2 material, and the coulomb efficiency rapidly approaches 100% in subsequent cycles, and remains stable in hundreds of cycles. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 It is a scanning electron microscope photo (a) and a transmission electron microscope photo (b) of the mesoporous SiO2 nanosphere in Example 1. Figure 1 Figure 1 It is a scanning electron microscope photo (a) and a transmission electron microscope photo (b) of the mesoporous SiO2 nanosphere in Example 1. Figure 2 It is a scanning electron microscope photo (a) and a transmission electron microscope photo (b) of the mesoporous SiO2 nanosphere in Example 1. Figure 2 Figure 2 It is a scanning electron microscope photo (a) and a transmission electron microscope photo (b) of the mesoporous SiO2 nanosphere in Example 1. Figure 3 It is a cycle performance curve of the SiO2@C composite material in Example 3. Figure 4 It is a cycle performance curve of the SiO2@C composite material in Example 3. DETAILED EMBODIMENTS EMBODIMENT
[0020] Take 0.1 g of cetyltrimethylammonium bromide into 120 mL of water, stir in a 35 °C water bath until completely dissolved. Then add 3 mL of tetraethyl orthosilicate and 1 mL of vinyltriethoxysilane. Stir the mixed solution in a 25 °C water bath for 7 h, then centrifuge, wash with deionized water three times, and put it in a 60 °C oven to dry for 24 h. Disperse the obtained white powder in 120 mL of water, add 12 mL of hydrochloric acid, and continue stirring at room temperature for 10 h. After centrifugation, washing, and drying, the amino-functionalized mesoporous SiO2 nanospheres are obtained. Take 3 g of tartaric acid into 100 mL of water, stir in a 25 °C water bath until completely dissolved. Then take 0.2 g of mesoporous SiO2 nanospheres and add them, ultrasonic dispersion is uniform. Continue stirring for 1 h to obtain dispersion A. Take 2 g of melamine into 100 mL of water, stir in a 35 °C water bath until completely dissolved to obtain solution B. Then, under stirring, quickly pour dispersion A into solution B, and gradually cool to room temperature. Continue stirring at room temperature for 24 h, then perform suction filtration, washing, and drying. Finally, place it in a tube furnace and calcine carbonize at 850 °C for 3 h to obtain two-dimensional structure nitrogen-doped SiO2@C composite materials. Example
[0021] Take 0.5 g of cetyltrimethylammonium bromide into 100 mL of water, stir in a 40 °C water bath until completely dissolved. Then add 2 mL of sodium metasilicate and 0.8 mL of vinyltrimethoxysilane. Stir the mixed solution in a 25 °C water bath for 7 h, then centrifuge, wash with deionized water three times, and put it in an 80 °C oven to dry for 24 h. Disperse the obtained white powder in 120 mL of water, add 12 mL of nitric acid, and continue stirring at room temperature for 8 h. After centrifugation, washing, and drying, the amino-functionalized mesoporous SiO2 nanospheres are obtained. Take 3 g of citric acid into 100 mL of water, stir in a 25 °C water bath until completely dissolved. Then take 0.4 g of mesoporous SiO2 nanospheres and add them, ultrasonic dispersion is uniform. Continue stirring for 1 h to obtain dispersion A. Take 2 g of pyrazole into 100 mL of water, stir in a 40 °C water bath until completely dissolved to obtain solution B. Then, under stirring, quickly pour dispersion A into solution B, and gradually cool to room temperature. Continue stirring at room temperature for 24 h, then perform suction filtration, washing, and drying. Finally, place it in a tube furnace and calcine carbonize at 900 °C for 1.5 h to obtain two-dimensional structure nitrogen-doped SiO2@C composite materials. Example
[0022] Take 0.5 g of cetylpyridinium bromide into 100 mL of water, stir in a 40 °C water bath until completely dissolved. Then add 2 mL of aluminum silicate and 1.2 mL of vinyltri(β-methoxyethoxy)silane. Stir the mixed solution in a 25 °C water bath for 7 h, then centrifuge, wash with deionized water three times, and put it in a 80 °C oven to dry for 24 h. Disperse the obtained white powder in 100 mL of water, add 10 mL of sulfuric acid and continue stirring at room temperature for 12 h. After centrifugation, washing and drying, amino-functionalized mesoporous SiO2 nanospheres are obtained. Weigh 3 g of benzoic acid into 100 mL of water, stir in a 25 °C water bath until completely dissolved. Then take 0.3 g of mesoporous SiO2 nanospheres and add them, ultrasonic dispersion is uniform. Continue stirring for 1 h to obtain dispersion A. Take 2 g of pyridine into 100 mL of water, stir in a 40 °C water bath until completely dissolved to obtain solution B. Then, under stirring, quickly pour dispersion A into solution B, gradually cool to room temperature. Continue stirring at room temperature for 24 h, then perform suction filtration, washing and drying. Finally, place it in a tube furnace and calcine at 800 °C for 2 h to obtain two-dimensional structure nitrogen-doped SiO2@C composite material. Example
[0023] Take 0.6 g of cetylpyridinium bromide into 100 mL of water, stir in a 40 °C water bath until completely dissolved. Then add 4 mL of aluminum silicate and 1.2 mL of vinyltrimethoxysilane. Stir the mixed solution in a 25 °C water bath for 10 h, then centrifuge, wash with deionized water three times, and put it in a 100 °C oven to dry for 24 h. Disperse the obtained white powder in 100 mL of water, add 10 mL of sulfuric acid and continue stirring at room temperature for 12 h. After centrifugation, washing and drying, amino-functionalized mesoporous SiO2 nanospheres are obtained. Weigh 3 g of benzoic acid into 100 mL of water, stir in a 25 °C water bath until completely dissolved. Then take 0.5 g of mesoporous SiO2 nanospheres and add them, ultrasonic dispersion is uniform. Continue stirring for 1 h to obtain dispersion A. Take 3 g of pyrrole into 100 mL of water, stir in a 40 °C water bath until completely dissolved to obtain solution B. Then, under stirring, quickly pour dispersion A into solution B, gradually cool to room temperature. Continue stirring at room temperature for 24 h, then perform suction filtration, washing and drying. Finally, place it in a tube furnace and calcine at 800 °C for 2 h to obtain two-dimensional structure nitrogen-doped SiO2@C composite material. Example
[0024] 0.3 g of cetyltrimethylammonium bromide was added to 140 mL of water, and stirred in a 40 °C water bath until completely dissolved. Then 2 mL of sodium metasilicate and 0.8 mL of vinyltriethoxysilane were added. The mixed solution was stirred in a 25 °C water bath for 9 h, and then centrifuged, washed with deionized water three times, and dried in a 60 °C oven for 24 h. The obtained white powder was dispersed in 100 mL of water, and 10 mL of hydrochloric acid was added. The mixture was stirred at room temperature for 10 h. After centrifugation, washing, and drying, the amino-functionalized mesoporous SiO2 nanospheres were obtained. 3 g of tartaric acid was weighed and added to 100 mL of water, and stirred in a 25 °C water bath until completely dissolved. Then 0.3 g of mesoporous SiO2 nanospheres was added, and ultrasonically dispersed. After 1 h of continuous stirring, dispersion liquid A was obtained. 2.5 g of pyridine was added to 100 mL of water, and stirred in a 40 °C water bath until completely dissolved to obtain solution B. Then, under stirring, dispersion liquid A was quickly poured into solution B, and gradually cooled to room temperature. After 24 h of continuous stirring at room temperature, suction filtration was performed. After suction filtration, washing, and drying, it was placed in a tube furnace and calcined at 900 °C for 3 h to obtain two-dimensional structure nitrogen-doped SiO2@C composite material.
[0025] The above detailed description of the preparation method of a two-dimensional carbon structure anchoring mesoporous silica nanosphere composite material and its application as a lithium ion battery negative electrode material is illustrative rather than limiting, and several examples can be listed within the defined range. Therefore, changes and modifications without departing from the overall concept of the present application shall be within the scope of protection of the present application.
Claims
1. A method for preparing a mesoporous silica nanosphere composite material, characterized in that, The method comprises the following steps: 1) a certain amount of silane coupling agent and silicon source are added dropwise into an aqueous solution containing a cationic surfactant to obtain a reaction solution, and after the liquid phase reaction is completed, the amino-functionalized mesoporous SiO2 nanospheres are prepared by filtration, acid washing and drying; The concentration of the silane coupling agent in the reaction solution is 0.03-0.2 mol / L; The concentration of the silicon source in the reaction solution is 0.1-0.3 mol / L; The concentration of the cationic surfactant in the reaction solution is 0.1-0.3 mol / L; 2) the obtained mesoporous SiO2 nanospheres are ultrasonically dispersed in an aqueous solution containing a carboxylic acid to obtain a dispersion A; The SiO2 nanosphere content in the dispersion A is 2%-10%; The concentration of the carboxylic acid in the dispersion A is 0.3-0.5 mol / L; 3) an organic compound containing a nitrogen-containing heterocycle is dissolved in water to obtain a solution B; The concentration of the organic compound containing a nitrogen-containing heterocycle in the solution B is 0.15-0.25 mol / L; 4) the dispersion A and the solution B are mixed, and after the amidation reaction is completed, the precipitate is obtained by filtration, washing and drying; The amidation reaction temperature is 25-40 DEG C, and the time is 20-35 h; 5) the precipitate is subjected to a carbonization reaction under an argon atmosphere, and the nitrogen-doped SiO2@C composite material is obtained. The carbonization reaction temperature is 700-900 DEG C, and the time is 1.5-4 h.
3. The preparation method according to claim 1, characterized in that, In step 1), the silane coupling agent includes vinyltriethoxysilane, vinyltrimethoxysilane and vinyltri(β-methoxyethoxy)silane, but is not limited to the above-mentioned substances; the silicon source includes tetraethyl orthosilicate, sodium metasilicate and aluminum silicate, but is not limited to the above-mentioned substances; and the cationic surfactant includes ester quaternary ammonium salt, ethoxylamine and dialkyldimethyl quaternary ammonium salt, but is not limited to the above-mentioned substances.
4. The production method according to claim 1, characterized by, In step 1), the silane coupling agent includes vinyltriethoxysilane, vinyltrimethoxysilane and vinyltri(β-methoxyethoxy)silane, but is not limited to the above-mentioned substances; the silicon source includes tetraethyl orthosilicate, sodium metasilicate and aluminum silicate, but is not limited to the above-mentioned substances; and the cationic surfactant includes ester quaternary ammonium salt, ethoxylamine and dialkyldimethyl quaternary ammonium salt, but is not limited to the above-mentioned substances.
5. The preparation method according to claim 1, characterized in that, In step 1), the acid used for acid washing is one or more of hydrochloric acid, sulfuric acid and nitric acid, and the concentration is 0.5-2 mol / L.
6. The method of claim 1, wherein, In step 1), the liquid phase reaction temperature is 35-50 DEG C, and the time is 7-15 h, and stirring is accompanied.
7. The preparation method according to claim 1, characterized in that, In step 1), the product drying process is carried out in an oven at 60-100 DEG C.
8. The method of claim 1, wherein, In step 2), the carboxylic acid includes tartaric acid, citric acid and benzoic acid, but is not limited to the above-mentioned substances.
9. The method of claim 1, wherein, In step 3), the organic compound containing a nitrogen-containing heterocycle includes melamine, pyrazole, pyridine and pyrrole, but is not limited to the above-mentioned substances.
10. The method of claim 1, wherein, In step 4), the amidation reaction is accompanied by stirring.
11. The method of claim 1, wherein, In step 4), the washing agent is deionized water and ethanol, and the drying process is carried out in an oven at 60-100 DEG C.
12. The method of claim 1, wherein, In step 5), the inert gas is one or more of nitrogen, argon and helium, and the flow rate is 30-75 sccm.
13. Use of the two-dimensional carbon structure-anchored mesoporous silica nanosphere composite prepared by the method according to any one of claims 1-7 as a negative electrode material for lithium ion batteries.