阅读说明：本技术 一种固态钒电解质的制备方法 (Preparation method of solid vanadium electrolyte ) 是由 张忠裕 秦野 张博 唐彪 刘建国 赵锋 吴晓亮 刘磊 严川伟 刘在波 于 2019-11-01 设计创作，主要内容包括：本发明涉及电池应用及能量恢复技术领域,且公开了一种固态钒电解质的制备方法,以含钒浸出液为原料,经过还原、浓缩和提纯,制得3.5价钒溶液,在高真空度条件下,将溶液至于液氮中,将结冰体中水分升华,使溶液干燥成粉态物料,含钒浸出液为钒矿渣钠化焙烧、水浸产物,含钒量为50g/L-100g/L,pH值为6-8。该固态钒电解质的制备方法,通过以含钒浸出液为原料,经过还原、浓缩和提纯,制得3.5价钒溶液,在高真空度条件下,将溶液至于液氮中,将结冰体中水分升华,使溶液干燥成粉态物料,本申请以含钒浸出液为原料,采用化学-电化学复合还原方法,在常压下进行,工艺简单,操作容易,原料易得,可以明显降低还原反应能耗。(The invention relates to the technical field of battery application and energy recovery, and discloses a preparation method of a solid vanadium electrolyte, which comprises the steps of taking vanadium-containing leachate as a raw material, reducing, concentrating and purifying to obtain a 3.5-valent vanadium solution, placing the solution into liquid nitrogen under the condition of high vacuum degree, subliming water in an ice body, drying the solution into a powdery material, wherein the vanadium-containing leachate is a sodium roasting and water leaching product of vanadium slag, the vanadium content is 50-100 g/L, and the pH value is 6-8. The preparation method of the solid vanadium electrolyte comprises the steps of taking vanadium-containing leachate as a raw material, reducing, concentrating and purifying to obtain a 3.5-valent vanadium solution, placing the solution into liquid nitrogen under a high vacuum degree condition, subliming water in an ice body, and drying the solution into a powdery material.)

1. A method for preparing solid vanadium electrolyte is characterized in that leaching solution containing vanadium is used as a raw material, reduction, concentration and purification are carried out to prepare 3.5-valent vanadium solution, the solution is placed in liquid nitrogen under the condition of high vacuum degree, water in an icing body is sublimated, and the solution is dried into powder material.

2. The method according to claim 1, wherein the vanadium-containing leachate is a product of sodium roasting and water leaching of vanadium slag, contains 50g/L to 100g/L of vanadium, and has a pH of 6 to 8.

3. The method according to claim 2, wherein the vanadium ions in the leachate are stably released in the form of +5 negative ions in the solution, and certain amounts of calcium, magnesium, silicon, iron and titanium ions exist.

4. The method for preparing the solid vanadium electrolyte according to claim 1, wherein an electrochemical-chemical combined reduction method is adopted, and an auxiliary reducing agent is introduced during electrolysis to increase the conductivity of the solution and participate in chemical reaction, so that vanadium in the vanadium leachate is in a 3.5-valent state.

5. The method of claim 4, wherein an auxiliary reducing agent is introduced, which is one or more of sodium chloride, sodium bisulfite, sodium hydroxide, sodium pyrosulfate, sodium thiosulfate, and sodium carbonate.

6. The method for preparing a solid vanadium electrolyte according to claim 4, wherein a 3.5-valent vanadium solution is prepared, wherein the pH value of the solution is 3 to 5.

7. The method for preparing a solid vanadium electrolyte according to claim 1, wherein a membrane concentration method is used to increase the vanadium content in the solution and reduce the content of the impurity ions in the solution at the right time.

8. The method for preparing the solid vanadium electrolyte according to claim 7, wherein a nanofiltration membrane is used as a medium, and the concentration amount of the solution and the permeability of impurities are adjusted under a pressure of 10-100 kg.

9. The method for preparing the solid vanadium electrolyte according to claim 1, wherein the method comprises removing impurities in the solution by ion exchange twice, immersing the solution in liquid nitrogen under vacuum degree of-50 Kpa under vacuum condition, and operating for 1 hour to obtain powder material.

10. The method for preparing a solid vanadium electrolyte according to claim 8, wherein the mixed bed softened resin is used for multiple filtration.

Technical Field

The invention relates to the technical field of battery application and energy recovery, in particular to a preparation method of a solid vanadium electrolyte.

Background

An all-vanadium redox flow battery, referred to as a vanadium battery for short. Compared with the traditional storage battery, the electrochemical energy storage system has the characteristics of rapid and high-capacity charge and discharge, low self-discharge rate, simple battery structure and the like, and is an ideal power supply form for large-scale energy storage of novel energy sources such as wind energy, solar energy and the like. The electrolyte of the positive electrode and the negative electrode of the vanadium battery is VO-containing²⁺/VO₂ ⁺And V²⁺/V³⁺The sulfuric acid solution of the redox couple, which is not only a conductive medium but also an electroactive substance for realizing energy storage, is the core of energy storage and energy conversion of the vanadium battery. The concentration of vanadium ions is the most important factor in determining the energy density of the battery. Because the phenomena of precipitation and coagulation of vanadium species and the like occur in practical use, the current use concentration of the electrolyte of the vanadium battery is about 1.5mol/L, and the energy density is low (25Wh/kg), so that the high-concentration electrolyte solution is actually required to realize the high specific energy of the battery, and the high-concentration electrolyte solution is required to have high stability, which is a key technical problem that the vanadium battery is urgently required to be solved in the practical stage.

At present, the preparation method of the adopted electrolyte mainly comprises the following steps: will V₂O₅Mixing with a certain amount of concentrated sulfuric acid, and electrolyzing to obtain VOSO₄Solution, then charging and discharging the battery; mixing concentrated sulfuric acid with distilled water according to the weight ratio of 1: 1 in a weight ratio ofDiluting, adding V₂O₃Then gradually adding V₂O₅Cooling and filtering to obtain blue VOSO₄Acid solution, then charging and discharging the battery; adding VOSO₄Directly dissolving in sulfuric acid (1-9mol/L), and then charging and discharging the battery; reacting NH₄VO₃Dissolving in concentrated sulfuric acid with certain concentration to obtain VO²⁺、V³⁺、NH₄ ⁺、SO₄ ^2-The coexisting system can directly charge and discharge the battery to obtain the electrolyte required by the anode and the cathode, but the electrolyte solution of the conventional flow battery is difficult to transport, and the solution storage and stability are poor, so that the preparation method of the solid vanadium electrolyte is provided.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a preparation method of a solid vanadium electrolyte, which has the advantages of convenience in transportation and the like and solves the problems of difficulty in transportation, poor solution storage and poor stability of the electrolyte solution of the conventional flow battery.

(II) technical scheme

In order to realize the purpose of convenient transportation, the invention provides the following technical scheme: a process for preparing solid vanadium electrolyte includes such steps as reducing the extracted liquid containing vanadium, concentrating, purifying to obtain 3.5-valent vanadium solution, loading it in liquid nitrogen, sublimating the water in frozen body, and drying.

Preferably, the vanadium-containing leaching solution is a product of sodium roasting and water leaching of vanadium slag, the vanadium content is 50g/L-100g/L, and the pH value is 6-8.

Preferably, vanadium ions in the leaching solution are stably released in the solution in a +5 negative ion form, and certain amounts of calcium, magnesium, silicon, iron and titanium ions exist.

Preferably, an electrochemical-chemical combined reduction method is adopted, and an auxiliary reducing agent is introduced during electrolysis to increase the conductivity of the solution and participate in chemical reaction, so that the vanadium in the vanadium leaching solution is in a 3.5-valent state.

Preferably, an auxiliary reducing agent is introduced, which is one or more than two of sodium chloride, sodium bisulfite, sodium hydroxide, sodium pyrosulfate, sodium thiosulfate and sodium carbonate.

Preferably, the pH value of the 3.5-valent vanadium solution is 3-5.

Preferably, a membrane concentration method is adopted to improve the vanadium content in the solution and timely reduce the content of the impurity ions in the solution.

Preferably, a nanofiltration membrane is used as a medium, and the concentration amount of the solution and the impurity transmittance are adjusted under the pressure of 10-100 kg.

Preferably, removing the impurity ions in the solution for the second time by adopting an ion exchange impurity removal method, immersing the solution into liquid nitrogen under the condition of vacuumizing, and operating for 1 hour under the vacuum degree of-50 Kpa to obtain the powder material.

Preferably, multiple filtrations are performed using the mixed bed softened resin.

(III) advantageous effects

Compared with the prior art, the invention provides a preparation method of a solid vanadium electrolyte, which has the following beneficial effects:

1. the preparation method of the solid vanadium electrolyte comprises the steps of taking vanadium-containing leachate as a raw material, reducing, concentrating and purifying to obtain a 3.5-valent vanadium solution, placing the solution into liquid nitrogen under a high vacuum degree condition, subliming water in an ice body, and drying the solution into a powdery material.

2. The preparation method of the solid vanadium electrolyte comprises the steps of taking vanadium-containing leachate as a raw material, carrying out reduction, concentration and purification to prepare a 3.5-valent vanadium solution, placing the solution into liquid nitrogen under a high vacuum degree condition, subliming water in an ice body, and drying the solution into a powdery material.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.