阅读说明：本技术 一种原子取代效应诱导金属氧化物内晶格畸变的方法 (Method for inducing lattice distortion in metal oxide by atomic substitution effect ) 是由 严乙铭 王诗雨 杨志宇 姚舒允 刘若琛 于 2021-08-05 设计创作，主要内容包括：一种原子取代效应诱导金属氧化物内晶格畸变的方法,属于材料制备领域。本发明通过将升华硫粉与锰氧化物混合煅烧引入晶格畸变,从而提高了锰氧化物电极材料的电化学性能和稳定性,该方法制备安全,简单,易于操作。(A method for inducing lattice distortion in metal oxide by an atomic substitution effect belongs to the field of material preparation. The method introduces lattice distortion by mixing and calcining the sublimed sulfur powder and the manganese oxide, thereby improving the electrochemical performance and stability of the manganese oxide electrode material.)

1. A method for inducing lattice distortion in metal oxide by atom substitution effect is characterized in thatThe method comprises the following steps: adding Mn (NO)₃)₂Preparing into aqueous solution, adding 1mol/L sodium hydroxide, adjusting pH to 8-11, preferably 9, stirring, and adding H₂O₂Solution, a large amount of bubbles and precipitate formation was observed; then putting the reaction system into an ultrasonic pool for continuous ultrasonic or/and mechanical stirring; finally, washing and filtering the obtained product by deionized water, and drying to obtain a precursor material; mixing the precursor material with sublimed sulfur powder, putting the mixture into a tube furnace, and reacting the mixture in a reactor N₂Calcining for 2 hours in the atmosphere, washing the calcined material with cyclohexane, and desulfurizing; finally, washing and filtering the obtained product by using deionized water and ethanol respectively, and drying to obtain a product with distorted crystal lattices.

2. A method of inducing lattice distortion in metal oxides by an atomic substitution effect as claimed in claim 1, wherein each 0.3-0.5g of Mn (NO)₃)₂Corresponds to 30% of H₂O₂The solution was 1 mL.

3. A method for inducing lattice distortion in metal oxides by using atomic substitution effect according to claim 1, wherein the mass ratio of the precursor material to the sublimed sulfur powder is 1 (0.01-10), preferably 1: 1.

4. The method for inducing lattice distortion in a metal oxide by an atomic substitution effect as claimed in claim 1, wherein the tube furnace is heated at a rate of 5 ℃/min and a final temperature of 200 ℃.

5. Lattice-distorted Mn obtainable by a process according to any one of claims 1 to 4₃O₄。

6. Lattice-distorted Mn obtainable by a process according to any one of claims 1 to 4₃O₄For use as an electrode material.

The technical field is as follows:

the invention belongs to the field of material preparation, and particularly relates to a metal oxide with lattice distortion and a preparation method thereof.

Background

With the rapid development of industrialization in modern society, the demand of human beings for fossil fuels is increasing day by day, which causes serious energy consumption and environmental pollution, and greatly promotes the research and development of clean energy and renewable energy storage equipment. Supercapacitors (SCs) are recognized as highly efficient electrical energy storage devices due to their excellent rate capability, long cycle life, and ultra-high power density. However, the development of SCs has been limited due to the lack of stable electrode materials to achieve higher energy/power densities and longer cycle life.

Transition metal oxides have been extensively studied for their high capacitance pseudocapacitive charge storage mechanism. Wherein Mn is₃O₄The material is a promising candidate material due to the characteristics of high abundance, environmental friendliness and high theoretical specific capacitance, however, the practical application of the material is limited by low conductivity, large volume change and easy agglomeration in the reaction process. In recent years, Mn has been improved₃O₄The charge transfer kinetics of the electrode, however, Mn has taken various strategies, such as bonding to a conductive carbon matrix, reducing the particle size, preparing a porous network, etc₃O₄There is still room for improvement in performance of (c).

Disclosure of Invention

The primary object of the present invention is to prepare a lattice-distorted Mn₃O₄The electrode material improves the stability and electrochemical performance of the manganese oxide.

In order to achieve the above object, the present invention adopts the following technical means.

A method of inducing lattice distortion in a metal oxide by an atomic substitution effect, comprising the steps of: adding Mn (NO)₃)₂Preparing into aqueous solution, adding 1mol/L sodium hydroxide, adjusting pH to 8-11, preferably 9, stirring, and adding H₂O₂Solution, a large amount of bubbles and precipitate formation was observed; then putting the reaction system into an ultrasonic pool for continuous ultrasonic or/and mechanical stirring; finally, washing and filtering the obtained product by deionized water, and drying to obtain a precursor material; mixing the precursor material with sublimed sulfur powder, putting the mixture into a tube furnace, and reacting the mixture in a reactor N₂Calcining for 2 hours in the atmosphere, washing the calcined material with cyclohexane, and desulfurizing; finally, washing and filtering the obtained product by using deionized water and ethanol respectively, and drying to obtain a product with distorted crystal lattices.

Every 0.3-0.5g of Mn (NO)₃)₂Corresponds to 30% of H₂O₂1mL of solution; mn (NO)₃)₂The mass percentage concentration of the aqueous solution can be as long as the solution can be formed, such as 0.05-2%; precursor material and sublimed sulfur powderThe mass ratio of (A) to (B) is 1 (0.01-10), preferably 1: 1.

The reaction time of continuous ultrasound or/and mechanical stirring may be from 5min to several days, such as 5 days.

The rate of temperature rise of the tube furnace was 5 ℃/min and the final temperature was 200 ℃.

The structural distortion strategy provided by the invention can promote charge transfer and improve the conductivity and redox activity of the electrode material. Mn having a slight lattice distortion was successfully synthesized by a simple sulfurization/desulfurization treatment₃O₄. Mn obtained₃O₄Fine lattice distortion (Ov-Mn)₃O₄) With delocalized electron configuration and narrow band gap, electron transfer is significantly accelerated. The tiny lattice distortion can effectively reduce the ion diffusion energy barrier and promote Na⁺Transport kinetics. The results show that the product is at 1A g^-1Under the condition of Ov-Mn₃O₄Na of (2)⁺Storage capacity of 331.1F g^-1At 20A g^-1Under the condition of Na⁺Storage capacity of 258.2F g^-1In 15000 cycles, Na thereof⁺The storage capacity retention rate was 83%. Based on Ov-Mn₃O₄Asymmetric Supercapacitor (ASC) at cathode with power density of 1000W kg^-1When the feed is used, 52.5Wh kg of feed can be provided^-1The energy density of (1).

Drawings

FIG. 1 shows the result of obtaining Mn with lattice distortion₃O₄SEM and TEM images of the material;

FIG. 2 shows Mn obtained by lattice distortion₃O₄Material (calcined with sublimed sulphur powder) Mn₃O₄XRD comparison of materials (calcined without sublimed sulphur powder)

Figure 3 compares the addition of Raman with calcination without sublimed sulphur powder.

FIG. 4 compares the Mn 3s of XPS calcined without sublimed sulfur powder.

FIG. 5 compares the addition of EPR calcined without sublimed sulfur powder.

FIG. 6 results of cyclic voltammetry tests with and without calcination of sublimed sulfur powder (scan rate of 5mV s)^-1) And the result of constant current charge and discharge test (current density of 1A g)^–1)。

Detailed Description

The present invention will be further illustrated with reference to the following examples, but the present invention is not limited to the following examples.

Example 1

Adding Mn (NO)₃)₂Preparing aqueous solution, adding 1mol/L sodium hydroxide, adjusting pH to 9, stirring, adding H₂O₂Solution, a large amount of bubbles and precipitate formation was observed; then putting the reaction system into an ultrasonic pool for continuous ultrasonic or/and mechanical stirring; finally, washing and filtering the obtained product by deionized water, and drying to obtain a precursor material; mixing the precursor material with sublimed sulfur powder, putting the mixture into a tube furnace, and reacting the mixture in a reactor N₂Calcining for 2 hours in the atmosphere, washing the calcined material with cyclohexane, and desulfurizing; finally, washing and filtering the obtained product by using deionized water and ethanol respectively, and drying to obtain a product with distorted crystal lattices.

Every 0.4g Mn (NO)₃)₂Corresponds to 30% of H₂O₂1mL of solution; mn (NO)₃)₂The mass percentage concentration of the aqueous solution is 1 percent; the mass ratio of the precursor material to the sublimed sulfur powder is 1: 1.

The reaction time of continuous ultrasonic or/and mechanical stirring is 10 h.

The rate of temperature rise of the tube furnace was 5 ℃/min and the final temperature was 200 ℃.

At 1A g^-1Under the condition of Ov-Mn₃O₄Na of (2)⁺Storage capacity of 331.1F g^-1At 20A g^-1Under the condition of Na⁺Storage capacity of 258.2F g^-1In 15000 cycles, Na thereof⁺The storage capacity retention rate was 83%. Based on Ov-Mn₃O₄Asymmetric Supercapacitor (ASC) at cathode with power density of 1000W kg^-1When the feed is used, 52.5Wh kg of feed can be provided^-1The energy density of (1).