阅读说明：本技术 一种光催化剂及其在动力电池光催化环保处理中的应用 (Photocatalyst and application thereof in photocatalytic environment-friendly treatment of power battery ) 是由 余海军 彭挺 谢英豪 张学梅 于 2020-06-24 设计创作，主要内容包括：本发明公开了一种光催化剂及其在动力电池光催化环保处理中的应用,所述光催化剂是由Ag-TaON负载在空心玻璃微珠上得到；所述Ag-TaON和空心玻璃微珠的质量比为1:(5-10)。本发明采用Ag-TaON和空心玻璃微珠进行复合,空心玻璃微珠对光有更好的透过性,不会造成催化剂之间的相互遮挡,这使得反应器内部填充的光催化剂被充分激发,能有效提高光的利用率,从而提高光催化剂的催化转化效率。(The invention discloses a photocatalyst and application thereof in photocatalytic environment-friendly treatment of a power battery, wherein the photocatalyst is obtained by loading Ag-TaON on hollow glass beads; the mass ratio of the Ag-TaON to the hollow glass bead is 1 (5-10). According to the invention, Ag-TaON and the hollow glass beads are compounded, the hollow glass beads have better light transmittance, and mutual shielding among catalysts can not be caused, so that the photocatalyst filled in the reactor is fully excited, the utilization rate of light can be effectively improved, and the catalytic conversion efficiency of the photocatalyst is improved.)

1. The photocatalyst is characterized in that the photocatalyst is obtained by loading Ag-TaON on hollow glass beads; the mass ratio of the Ag-TaON to the hollow glass bead is 1 (5-10).

2. The photocatalyst as set forth in claim 1, wherein the hollow glass microspheres have a particle size of 10 μm to 10 mm.

3. The method for preparing a photocatalyst as claimed in any one of claims 1 or 2, characterized by comprising the steps of:

(1) grinding TaON into powder, dispersing in a solvent, adding soluble silver salt, stirring, illuminating, centrifuging and washing to obtain an Ag-TaON catalyst;

(2) dispersing the Ag-TaON catalyst in a sodium tripolyphosphate solution, adding hollow glass beads, stirring and sintering to obtain the photocatalyst with Ag-TaON loaded on the hollow glass beads.

4. The method according to claim 3, wherein the solvent in the step (1) is water and methanol; the mass ratio of TaON, water and methanol is 1: (20-60): (15-40); the soluble silver salt is AgNO₃And (3) solution.

5. The method according to claim 3, wherein the sintering temperature in step (2) is 200-300 ℃, the atmosphere is nitrogen atmosphere, and the time is 1-2 hours.

6. The method of claim 3, wherein the TaON is prepared by the steps of:

(1) pretreating the tantalum foil;

(2) cooling, introducing inert gas, introducing reaction gas A, heating, and reacting to obtain Ta₂O₅；

(3) Cooling, introducing inert gas, introducing reaction gas B, heating, and carrying out heat preservation reaction to obtain TaON; in the step (2), the reaction gas A is O₂And N₂The mixed gas of (3); in the step (3), the reaction gas B is NH₃And N₂The mixed gas of (1).

7. The preparation method according to claim 6, wherein the pretreatment in step (1) comprises the following specific steps: pushing the corundum porcelain boat containing tantalum foil into the middle heating section of the tube furnace, sealing with a flange, and heating at room temperature for 2-30 mL/min^-1Introducing inert gas at the flow rate of 20-120 min; switching the gas path at 2-30 mL/min^-1Introducing the pretreatment gas at the flow rate of 2-8 ℃ for min^-1The temperature is raised to 250-350 ℃ at the speed, and the temperature is kept for 30-150 min; the pretreatment gas is H₂And N₂The mixed gas of (1).

8. The method according to claim 6, wherein the inert gas in the steps (2) and (3) is pure N₂And at least one of Ar or He.

9. A photocatalytic environment-friendly treatment method for a power battery is characterized by comprising the following steps:

(1) disassembling the waste lithium battery, and pyrolyzing to obtain electrolyte-mixed gas;

(2) introducing the electrolyte-entrained gas into a cleaning solution, introducing the electrolyte-entrained gas into a reactor containing the photocatalyst of claim 1 or 2, irradiating the electrolyte-entrained gas with a light source to carry out photocatalysis, and degrading the electrolyte-entrained gas into CO₂And H₂O。

10. The method as claimed in claim 9, wherein the cleaning solution is NaOH, Ca (OH)₂Or at least one of KOH.

Technical Field

The invention belongs to the field of catalysts, and particularly relates to a photocatalyst and application thereof in photocatalytic environment-friendly treatment of a power battery.

Background

Lithium battery electrolytes are carriers for ion transport in batteries. Generally consisting of a lithium salt and an organic solvent. The electrolyte plays a role in conducting ions between the positive electrode and the negative electrode of the lithium battery. The electrolyte is prepared from high-purity organic solvent, electrolyte lithium salt, necessary additives and other raw materials according to a certain proportion under a certain condition.

The electrolyte of the lithium battery is a liquid with electrolyte dissolved in an organic solvent. The electrolyte is typically lithium perchlorate, lithium hexafluorophosphate, or the like. The organic solvent is usually a liquid organic substance of the carbonate type. The electrolyte is organic volatile liquid, has obvious corrosivity, and can cause serious damage to respiratory tract after long-time inhalation. During the recovery treatment of the lithium ion battery, the lithium ion battery needs to be properly collected and treated, the volatilization and dissipation of the electrolyte are strictly controlled, and the harm to the human health and the ecological environment is avoided.

The traditional method for treating the electrolyte is to place the lithium ion battery in a pyrolysis furnace, so that the electrolyte and other organic matters are pyrolyzed simultaneously. However, the traditional recovery method, such as "an oxygen-free cracking recovery and sorting process for lithium battery" (CN201810712762.2), cannot treat the electrolyte alone, and the diaphragm is also pyrolyzed and removed during pyrolysis, so that the diaphragm cannot be effectively recovered, the resource recovery rate is low, and the limitation is obvious. The problems of low catalytic conversion efficiency, high catalyst cost and low degradation rate exist when the current catalyst is used for catalyzing and degrading the electrolyte.

Disclosure of Invention

The invention aims to provide a photocatalyst and application thereof in photocatalytic environment-friendly treatment of a power battery.

In order to achieve the purpose, the invention adopts the following technical scheme:

a photocatalyst is obtained by loading Ag-TaON on hollow glass microspheres; the mass ratio of the Ag-TaON to the hollow glass bead is 1 (5-10).

Preferably, the particle size of the hollow glass microspheres is 10 μm to 10 mm.

Preferably, the hollow glass beads comprise the following chemical components in percentage by mass: 45-90% SiO₂、5-50％Al₂O₃、4-10％K₂O, 1-10% CaO and 0-12% B₂O₃。

A preparation method of a photocatalyst comprises the following steps:

(1) grinding TaON into powder, dispersing in a solvent, adding soluble silver salt, stirring, illuminating, centrifuging and washing to obtain an Ag-TaON catalyst;

(2) dispersing the Ag-TaON catalyst in a sodium tripolyphosphate solution, adding hollow glass beads, stirring, drying and sintering to obtain the photocatalyst with Ag-TaON loaded on the surfaces of the hollow glass beads.

Preferably, the solvent in step (1) is water and methanol; the mass ratio of TaON, water and methanol is 1: (20-60): (15-40).

Preferably, the soluble silver salt in step (1) is AgNO₃And (3) solution.

More preferably, the AgNO₃The concentration of the solution is 0.5-1 mol.L^-1。

Preferably, the illumination in step (1) is performed by using a high-pressure mercury lamp under nitrogen atmosphere for 10-30 min.

Preferably, the concentration of the sodium tripolyphosphate solution in the step (2) is 0.1-1 mol.L^-1。

Preferably, the rotation speed of the stirring in the step (2) is 400-800r/min, and the time is 20-60 min.

Preferably, the sintering temperature in the step (2) is 200-300 ℃, the atmosphere is nitrogen atmosphere, and the time is 1-2 hours.

Preferably, the TaON is prepared by the following steps:

(1) pretreating the tantalum foil;

(2) cooling, introducing inert gas, introducing reaction gas A, heating, and reacting to obtain Ta₂O₅；

(3) Cooling, introducing inert gas, introducing reaction gas B, heating, and carrying out heat preservation reaction to obtain TaON; in the step (2), the reaction gas A is O₂And N₂The mixed gas of (3); in the step (3), the reaction gas B is NH₃And N₂The mixed gas of (1).

Preferably, the specific process of the pretreatment in the step (1): pushing the corundum porcelain boat containing tantalum foil into the middle heating section of the tube furnace, sealing with a flange, and heating at room temperature for 2-30 mL/min^-1Introducing inert gas at the flow rate of 20-120 min; switching the gas path at 2-30 mL/min^-1Introducing the pretreatment gas at the flow rate of 2-8 ℃ for min^-1The temperature is raised to 250-350 ℃ at the speed rate, and the temperature is kept for 30-150 min.

More preferably, the pre-treatment gas is H₂And N₂The mixed gas of (3); said H₂The concentration is 5-10%.

Preferably, the temperature reduction in the step (2) and the step (3) is to reduce the temperature to normal temperature.

Preferably, the inert gas in step (2) and step (3) is pure N₂And at least one of Ar or He.

Preferably, the flow rate of the inert gas introduced in the step (2) and the step (3) is 2-30 mL-min^-1The time is 20-120 min.

Preferably, said O is₂The concentration of (A) is 5% -10%.

Preferably, the flow rate of the reaction gas A introduced in the step (2) is 2-30mL min^-1。

Preferably, the first and second electrodes are formed of a metal,the temperature rise in the step (2) is 500-600 ℃, and the rate of temperature rise is 2-8 ℃ min^-1。

Preferably, the time of the heat preservation reaction in the step (2) is 30-150 min.

Preferably, the NH is₃The concentration is 5-10%.

Preferably, the flow rate of the reaction gas A introduced in the step (3) is 2-30mL min^-1。

Preferably, the temperature of the temperature rise in the step (3) is 800-900 ℃, and the rate of the temperature rise is 2-8 ℃ min^-1。

Preferably, the time for the incubation reaction in step (3) is 180-300 min.

A photocatalytic environment-friendly treatment method for a power battery comprises the following steps:

(1) disassembling the waste lithium battery, and pyrolyzing to obtain electrolyte-mixed gas;

(2) introducing electrolyte-mixed gas into cleaning solution, introducing into reactor containing photocatalyst, irradiating with light source for photocatalysis, and degrading into CO₂And H₂O。

Preferably, the cleaning solution in the step (2) is NaOH or Ca (OH)₂Or at least one of KOH.

Preferably, the concentration of the cleaning solution in the step (2) is 0.1-1 mol.L^-1。

Preferably, the light source in step (2) is ultraviolet light.

The reactor with the photocatalyst is arranged on the roof of a factory building for lighting, the solar light can excite the catalyst to generate photo-generated charges so as to perform catalytic oxidation, and materials such as polyethylene, polypropylene and the like are cracked into small molecules.

Preferably, the loading of the reactor in step (2) is between 30% and 100%.

Advantageous effects

1. According to the invention, Ag-TaON and the hollow glass beads are compounded, and the hollow glass beads have better light transmittance, so that mutual shielding among catalysts is avoided, the photocatalyst filled in the reactor can be fully excited, the utilization rate of light can be effectively improved, and the catalytic conversion efficiency of the photocatalyst is improved.

2. The catalyst disclosed by the invention is combined with Ag in a photo-deposition mode, and compared with the traditional chemical reduction method, the catalyst can obtain smaller Ag particles, so that the Ag has larger dispersity, the atom utilization rate is improved, the dosage of Ag is reduced, and the catalyst cost is lower.

3. The Ag-TaON is used as a photocatalyst, the TaON photoresponse range can cover part of visible light, the introduction of Ag can play a role in enriching electrons, and the Ag-TaON catalyst can perform photocatalytic reaction under the action of the visible light.

4. The invention adopts Ag-TaON as a photocatalyst, adopts a photocatalytic technology to degrade electrolyte, leads the electrolyte into a photocatalytic reactor after defluorination by alkali liquor, and directly catalyzes and oxidizes organic matters in the electrolyte into CO under the action of photocatalysis₂And H₂And O, other agents are not required to be added in the treatment process, the treatment process is environment-friendly, safe and low in cost, and the treated tail gas is non-toxic and harmless and can be directly discharged.

Drawings

FIG. 1 is an SEM photograph of Ag-TaON powder in example 2 of the present invention;

FIG. 2 is an SEM image of a photocatalyst prepared in example 2 of the present invention;

FIG. 3 is an XRD pattern of Ag-TaON powder in example 2 of the present invention.

Detailed Description

In order to make the technical solutions of the present invention more apparent to those skilled in the art, the following examples are given for illustration. It should be noted that the following examples are not intended to limit the scope of the claimed invention.

The starting materials, reagents or apparatuses used in the following examples are conventionally commercially available or can be obtained by conventionally known methods, unless otherwise specified.