Oxygen vacancy modified metal oxide material as well as preparation method and application thereof
By reacting metal oxides with strong reducing agent solutions at room temperature and pressure, oxygen vacancy-modified metal oxide materials are prepared, solving the safety hazards and control difficulties of high-temperature and high-pressure methods, and achieving high energy storage performance of lithium-ion batteries.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XUZHOU NORMAL UNIVERSITY
- Filing Date
- 2026-01-05
- Publication Date
- 2026-04-28
AI Technical Summary
Existing technologies for preparing metal oxide materials using high-temperature and high-pressure oxygen vacancy preparation methods pose safety risks and are difficult to control precisely, failing to meet the high lithium storage capacity and cycle stability requirements of lithium-ion batteries.
Oxygen vacancy-modified metal oxide materials are prepared by reacting metal oxides with a strong reducing agent solution at room temperature and pressure, followed by standing, cleaning, and vacuum drying steps, thus achieving precise control of oxygen vacancy concentration.
Controllable preparation of oxygen vacancies was achieved at room temperature and pressure, applicable to various metal oxides, low cost and suitable for large-scale production, thus improving the energy storage performance of lithium-ion batteries.
Smart Images
Figure CN121929658A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to an oxygen vacancy-modified metal oxide material, its preparation method, and its application. Background Technology
[0002] With the increasing development of electric and hybrid vehicles, range anxiety has gradually become a major concern for consumers. Currently, lithium-ion batteries using graphite as the anode material cannot meet societal demands due to their low power output and limited lithium storage capacity. Oxide anode materials, with their high theoretical specific capacity, can significantly improve battery energy density, meeting the requirements of high-power applications such as electric vehicles. However, the crystal structure of metal oxides determines the diffusion path and rate of lithium ions, thus severely impacting the lithium storage capacity and cycle stability of lithium-ion batteries.
[0003] In recent years, oxygen vacancies have attracted considerable attention as a novel strategy for regulating electronic structure and interfacial coordination. On the one hand, oxygen vacancies can modulate the electronic structure of metal oxides, significantly enhancing electron migration rates; on the other hand, they can precisely control the local microenvironment of oxides at the atomic scale, thereby influencing ion insertion and extraction and ultimately optimizing the kinetics of electrochemical reactions. However, conventional methods for preparing oxygen vacancies typically involve high-temperature and high-pressure reduction reactions, such as calcining metal oxides at high temperatures in a hydrogen atmosphere, using the high temperature and pressure of hydrogen to strip oxygen atoms from the metal oxides, thus forming oxygen vacancies. However, such reactions involving high temperature and pressure pose serious safety risks and make precise control of oxygen vacancies difficult. Therefore, developing a universal oxygen vacancy preparation strategy for metal oxides is a critical technical challenge that urgently needs to be addressed. Summary of the Invention
[0004] The purpose of this invention is to provide an oxygen vacancy-modified metal oxide material, its preparation method, and its application. This method is simple, operates at room temperature and pressure, is low in cost, and has strong versatility, enabling large-scale production. More importantly, this method can precisely control the oxygen vacancy concentration of the metal oxide material by adjusting the reaction time and the raw material ratio. The oxygen vacancy-modified metal oxide material prepared can be applied in the field of energy storage.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing oxygen vacancy-modified metal oxide materials, comprising the following steps: S1. In an inert atmosphere, place the metal oxide in a container containing a strong reducing agent solution and let it stand for a period of time. After the reduction reaction is complete, remove the excess liquid from the upper layer of the container in the manual control box. The bottom of the container is the oxide powder. S2. Add cleaning agent to the container containing oxide powder in step S1, stir for a period of time and let stand to clean off the residual strong reducing agent on the oxide surface and remove the excess liquid in the upper layer of the container. S3. Repeat step S2 to clean repeatedly until the strong reducing agent remaining on the oxide surface is completely removed. S4. Collect the metal oxide material obtained in step S3 and transfer it to a vacuum drying oven for drying to obtain the oxygen vacancy modified metal oxide material.
[0006] Preferably, in step S1, the metal oxide is Li4Ti5O. 12 One of TiO2, CeO2, SnO2, SiO2, Nb2O3, Sb2O5, Nb2O5, V2O5, V2O3, and MoO3.
[0007] Preferably, in step S1, the strong reducing agent solution is one of n-butyllithium solution, tert-butyllithium solution, sec-butyllithium solution, and isobutyllithium solution; the concentration of the strong reducing agent solution is 0.01 mol / L-5 mol / L.
[0008] Preferably, in step S1, the mass ratio between the metal oxide and the strong reducing agent is 100:(5-16); the reaction time between the metal oxide and the strong reducing agent is 0.5h-300h.
[0009] Preferably, in step S1, the inert atmosphere is argon, nitrogen, or helium.
[0010] Preferably, in step S2, the cleaning agent is one or more of benzene, pentane, hexane, cyclohexane, n-hexane, diethyl ether, and tetrahydrofuran; the stirring time is 0.1h-5h.
[0011] Preferably, in step S3, the number of times the cleaning is repeated is 2-8 times.
[0012] Preferably, in step S4, the vacuum drying temperature is 35°C. o C-90 o C, vacuum drying time is 1-24h.
[0013] To achieve the above-mentioned objectives, the present invention also provides an oxygen vacancy-modified metal oxide material prepared by the above method.
[0014] To achieve the above-mentioned objectives, this invention also provides the application of oxygen vacancy-modified metal oxide materials prepared by the above method in the field of energy storage.
[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention is carried out at room temperature and pressure, the operating conditions are mild and controllable, the oxygen vacancy concentration is adjustable, and the method is applicable to most metal oxides, with strong universality. (2) The present invention has low cost, simple operation method, simple process, and can realize large-scale production; (3) The present invention has a wide range of applications, and the oxygen vacancy modified metal oxide materials prepared have broad application prospects in the field of energy storage. Attached Figure Description
[0016] Figure 1 Physical images of the materials provided in Comparative Example 1 and the materials prepared in Example 1 of this invention; Figure 2 TEM images of the materials provided in Comparative Example 1 and the materials prepared in Example 1 of this invention; Figure 3 The XRD patterns are of the materials provided in Comparative Example 1 and the materials prepared in Example 1 of this invention; Figure 4 The long-cycle curves of the material provided in Comparative Example 1 and the material prepared in Example 1 of this invention at a current of 5C are shown. Figure 5 Physical images of the materials provided in Comparative Example 2 and the materials prepared in Example 2 of this invention; Figure 6 The images show physical pictures of the materials provided in Comparative Example 3 and the materials prepared in Example 3 of this invention. Detailed Implementation
[0017] The present invention will be further described in detail below with reference to the embodiments.
[0018] Comparative Example 1 Weigh out 3g of lithium titanate (Li4Ti5O) 12 The powder was used as the material in Comparative Example 1.
[0019] Example 1 An oxygen vacancy-modified metal oxide (Li4Ti5O) 12 The preparation method of the material includes the following steps: S1. Weigh 3g of Li4Ti5O into a manual control box under an argon atmosphere. 12 The powder was placed in a beaker, and 10 ml of 0.2 mol / L sec-butyllithium solution was added to the beaker. After standing for 48 hours, the upper layer of solution was poured into another beaker (waste solution collector). The bottom of the beaker is the oxide powder. S2. Transfer 15 ml of tetrahydrofuran to the beaker containing oxide powder in step S1. Stir the powder in the beaker with a glass rod until it is evenly dispersed and let it stand for 5 hours. Use the high solubility of the cleaning agent to dissolve and clean the residual strong reducing agent on the oxide surface. Then pour the clear solution on the top layer into the beaker where the waste solution is collected. S3. Repeat step S2 to clean repeatedly until the strong reducing agent remaining on the oxide surface is completely removed. S4. Collect the metal oxide material obtained in step S3 and transfer it to a vacuum drying oven at 70°C. o Drying in C for 24 hours yields oxygen vacancy-modified metal oxide materials.
[0020] The analysis results of Embodiment 1 and Comparative Example 1 of the present invention are as follows: from Figure 1 It can be clearly observed that under the strong reducing attack of sec-butyllithium solution, the color of lithium titanate powder changed from white to black. This indicates that oxygen in the lithium titanate lattice was lost under the attack of sec-butyllithium, forming a large number of oxygen vacancies left in the lithium titanate lattice, which in turn affected its absorption of visible light and thus changed its color.
[0021] from Figure 2 As can be clearly observed in image a, the lithium titanate TEM image in Comparative Example 1 exhibits perfect lattice fringes, while from... Figure 2 As can be seen in b, the surface disorder in the TEM image of lithium titanate in Example 1 indicates that the oxygen in the surface lattice of lithium titanate is plundered under the attack of sec-butyllithium, which destroys the lattice stripes on the surface of lithium titanate and turns it into an amorphous surface structure.
[0022] from Figure 3 It can be observed that the characteristic diffraction peaks of the comparative materials obtained in Comparative Example 1 and Example 1 are consistent, indicating that the reduction reaction of sec-butyllithium with lithium titanate only occurs on the surface of the material and does not change the cell structure of lithium titanate.
[0023] Figure 4 The figures shown are the long-cycle curves of the material prepared in Example 1 and the comparative material obtained in Comparative Example 1 at a current density of 5C (1C = 175 mAh / g); from Figure 4 As can be clearly observed, the oxygen vacancy-modified lithium titanate material in Example 1 still exhibits a discharge specific capacity of 178 mAh / g after 1000 cycles at a current density of 5C, which is far higher than the performance of the lithium titanate material in Comparative Example 1. This fully demonstrates that the oxygen vacancies formed after the oxygen in the lithium titanate lattice is plundered under the attack of sec-butyllithium can serve as additional lithium storage sites, contributing additional specific capacity to the electrochemical reaction process.
[0024] Comparative Example 2 Weigh 5g of TiO2 powder as the material for Comparative Example 1.
[0025] Example 2 A method for preparing an oxygen vacancy-modified metal oxide (TiO2) material includes the following steps: S1. In a manual control box under an argon atmosphere, weigh 5g of TiO2 powder and place it in a beaker. Transfer 15ml of 0.5mol / L n-butyllithium solution to the beaker and let it stand for 24h. Then pour the upper layer of solution into another beaker (waste solution collector). The bottom of the beaker is the oxide powder. S2. Transfer 20 ml of n-hexane to the beaker containing oxide powder in step S1. Stir the powder in the beaker with a glass rod until it is evenly dispersed and let it stand for 5 hours. Use the high solubility of the cleaning agent to dissolve and clean the residual strong reducing agent on the oxide surface. Then pour the clear solution on the top layer into the waste solution collection beaker. S3. Repeat step S2 to clean repeatedly until the strong reducing agent remaining on the oxide surface is completely removed. S4. Collect the metal oxide material obtained in step S3 and transfer it to a vacuum drying oven at 60°C. o Drying at C for 8 hours yields oxygen vacancy-modified metal oxide materials.
[0026] The analysis results of Embodiment 2 and Comparative Example 2 of the present invention are as follows: from Figure 5 It can be clearly observed that under the attack of the strong reducing agent n-butyllithium solution, the color of TiO2 changed from white to black. This indicates that the oxygen in the TiO2 lattice was lost under the attack of n-butyllithium, forming a large number of oxygen vacancies left in the TiO2 lattice, which changed its absorption of visible light, causing it to change from white to black.
[0027] The material prepared in Example 2 and the comparative material obtained in Comparative Example 2 were subjected to long-cycle experiments at a current density of 1C (1C=200 mA / g). The experimental results show that the oxygen vacancy modified TiO2 material in Example 2 still exhibits a discharge specific capacity of 265 mAh / g after 500 cycles at a current density of 1C, which is much higher than the performance of the TiO2 material in Comparative Example 2. This fully demonstrates that the oxygen vacancies formed after the oxygen in the TiO2 lattice is plundered under the attack of n-butyllithium can serve as additional lithium storage sites and contribute additional specific capacity to the electrochemical reaction process.
[0028] Comparative Example 3 Weigh 6g of V2O5 powder as the material for Comparative Example 1.
[0029] Example 3 A method for preparing an oxygen vacancy-modified metal oxide (V2O5) material includes the following steps: S1. In a manual control box under an argon atmosphere, weigh 6g of V2O5 powder and place it in a beaker. Add 15ml of 1mol / L tert-butyllithium solution to the beaker. After standing for 72h, pour the upper layer of solution into another beaker (waste solution collector). The bottom of the beaker is the oxide powder. S2. Transfer 15 ml of benzene to the beaker containing oxide powder in step S1. Stir the powder in the beaker with a glass rod until it is evenly dispersed and let it stand for 5 hours. Use the high solubility of the cleaning agent to dissolve and clean the residual strong reducing agent on the oxide surface. Then pour the clear solution on the top layer into the waste solution collection beaker. S3. Repeat step S2 to clean repeatedly until the strong reducing agent remaining on the oxide surface is completely removed. S4. Collect the metal oxide material obtained in step S3 and transfer it to a vacuum drying oven at 70°C. o Drying at C for 24 hours yields oxygen vacancy-modified metal oxide materials.
[0030] The analysis results of Embodiment 3 and Comparative Example 3 of the present invention are as follows: from Figure 6 It can be clearly observed that under the attack of the strong reducing agent tert-butyllithium solution, the color of V2O5 changed from yellow to black. This indicates that the oxygen in the V2O5 lattice was taken away by the attack of tert-butyllithium, forming a large number of oxygen vacancies left in the V2O5 lattice, which changed its absorption of visible light and made it change from yellow to black.
[0031] The material prepared in Example 3 and the comparative material obtained in Comparative Example 3 were subjected to long-cycle experiments at a current density of 3C (1C=100 mA / g). The experimental results show that the oxygen vacancy modified V2O5 material in Example 3 still exhibits a discharge specific capacity of 370 mAh / g after 500 cycles at a current density of 3C, which is much higher than the performance of the V2O5 material in Comparative Example 3. This fully demonstrates that the oxygen vacancies formed after the oxygen in the V2O5 lattice is plundered under the attack of tert-butyllithium can serve as additional lithium storage sites and contribute additional specific capacity to the electrochemical reaction process.
Claims
1. A method for preparing an oxygen vacancy-modified metal oxide material, characterized in that, Includes the following steps: S1. In an inert atmosphere, place the metal oxide in a container containing a strong reducing agent solution and let it stand for a period of time. After the reduction reaction is complete, remove the excess liquid from the upper layer of the container in the manual control box. The bottom of the container is the oxide powder. S2. Add cleaning agent to the container containing oxide powder in step S1, stir for a period of time and let stand to clean off the residual strong reducing agent on the oxide surface and remove the excess liquid in the upper layer of the container. S3. Repeat step S2 to clean the oxide surface repeatedly until the strong reducing agent remaining on the oxide surface is completely removed. S4. Collect the metal oxide material obtained in step S3 and transfer it to a vacuum drying oven for drying to obtain the oxygen vacancy modified metal oxide material.
2. The method for preparing an oxygen vacancy-modified metal oxide material according to claim 1, characterized in that, In step S1, the metal oxide is Li4Ti5O 12 One of TiO2, CeO2, SnO2, SiO2, Nb2O3, Sb2O5, Nb2O5, V2O5, V2O3, and MoO3.
3. The method for preparing an oxygen vacancy-modified metal oxide material according to claim 1 or 2, characterized in that, In step S1, the strong reducing agent solution is one of n-butyllithium solution, tert-butyllithium solution, sec-butyllithium solution, and isobutyllithium solution; the concentration of the strong reducing agent solution is 0.01 mol / L-5 mol / L.
4. A method for preparing an oxygen vacancy-modified metal oxide material according to claim 1 or 2, characterized in that, In step S1, the mass ratio between the metal oxide and the strong reducing agent is 100:(5-16); the reaction time between the metal oxide and the strong reducing agent is 0.5h-300h.
5. A method for preparing an oxygen vacancy-modified metal oxide material according to claim 1 or 2, characterized in that, In step S1, the inert atmosphere is argon, nitrogen, or helium.
6. A method for preparing an oxygen vacancy-modified metal oxide material according to claim 1 or 2, characterized in that, In step S2, the cleaning agent is one or more of benzene, pentane, hexane, cyclohexane, n-hexane, diethyl ether, and tetrahydrofuran; the stirring time is 0.1h-5h.
7. A method for preparing an oxygen vacancy-modified metal oxide material according to claim 1 or 2, characterized in that, In step S3, the washing process is repeated 2-8 times.
8. A method for preparing an oxygen vacancy-modified metal oxide material according to claim 1 or 2, characterized in that, In step S4, the vacuum drying temperature is 35°C. o C-90 o C, vacuum drying time is 1-24h.
9. The oxygen vacancy-modified metal oxide material prepared by the preparation method according to any one of claims 1-8.
10. The application of the oxygen vacancy-modified metal oxide material as described in claim 9 in the field of energy storage.