Preparation process of vanadium battery electrolyte

Abstract

The invention discloses a vanadium battery electrolyte preparation technology, and relates to the field of vanadium battery electrolyte preparation, and the vanadium battery electrolyte preparation technology comprises the following steps: preparing an electrolyte A; a first additive and a second additive are added in the feeding reaction process, then filtering operation and activation operation are conducted, a third additive and a fourth additive are added in the activation process, and finally the liquid B is obtained; and mixing the solution A and the solution B, adjusting the valence state, preparing an AB electrolyte with the average valence state of vanadium ions of 3.51-3.69, and finally standing and activating. The problems of low vanadium ion utilization rate, low energy density, poor stability and low energy efficiency in the electrochemical reaction of the existing vanadium battery electrolyte are solved, the vanadium ion utilization rate and the energy density are greatly improved and the capacity retention rate and the stability of the all-vanadium redox flow battery are greatly improved by using the additive and mixing the electrolyte, and the cost is reduced. And more than two products are produced in one technological process, so that market requirements are met.

Description

Technical Field

[0001] The invention relates to the field of vanadium battery electrolyte preparation, and in particular to a vanadium battery electrolyte preparation process. Background Art

[0002] Vanadium flow battery is the most widely studied and applied flow battery. Its main advantages are: (1) It can easily realize large-scale energy storage: the energy of vanadium battery is all stored in the electrolyte. The tank volume and electrolyte concentration determine the capacity of vanadium battery. The electrolyte has good consistency, which can achieve large-scale energy storage at GWh level (1 million kWh); (2) Long service life: vanadium battery can be deeply discharged without damaging the battery. The battery has a long service life and the charge and discharge cycle life exceeds 20,000 times; (3) Good safety: vanadium battery has no explosion or fire hazard. Even if the positive and negative electrolytes are mixed, there is no danger. The electrolyte temperature will only rise slightly. It is a battery that will never explode. In addition, vanadium battery has the advantages of fast response speed, high power, high efficiency, and no memory effect. It is considered to be the "perfect battery" for large-scale energy storage.

[0003] However, the mainstream vanadium batteries currently on sale have disadvantages such as low vanadium ion utilization rate, low energy density, and low energy efficiency. Among them, the vanadium ion concentration of the mainstream vanadium battery electrolyte currently on the market is about 1.6mol / L, the energy density of the electrolyte is below 20Wh / L, and the vanadium ion utilization rate in the electrochemical reaction of the vanadium battery is only 50%-70%. How to improve the utilization rate and stability of vanadium ions participating in electrochemical reactions, significantly increase the utilization rate of vanadium ions, and further reduce costs are practical problems facing the development of vanadium batteries. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the existing vanadium battery electrolyte has the disadvantages of low vanadium ion utilization rate, low energy density, poor stability, low energy efficiency, etc. in the electrochemical reaction. The purpose is to provide a vanadium battery electrolyte preparation process, which solves the problems of low vanadium ion utilization rate, low energy density, poor stability, and low energy efficiency in the electrochemical reaction of the existing vanadium battery electrolyte.

[0005] A process for preparing a vanadium battery electrolyte, comprising:

[0006] preparing an electrolyte A solution in which the average valence of vanadium ions is 3.5;

[0007] Preparation of liquid B with an average valence of vanadium ions of 4.0: firstly, a feed reaction is performed, during which additives No. 1 and No. 2 are added, stirring and temperature is controlled, and then filtering and activation are performed, during which additives No. 3 and No. 4 are added, and finally liquid B with an average valence of vanadium ions of 4.0 is obtained;

[0008] Liquid A and liquid B are mixed to adjust the valence state, and an AB electrolyte having an average valence state of vanadium ions of 3.51 to 3.69 is prepared, and finally the electrolyte is placed for activation.

[0009] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0010] 1. Greatly improve the utilization rate and energy density of vanadium ions: by adding additives No. 1, No. 2, No. 3 and No. 4 and by the synergistic cooperation between the additives, the electrolyte prepared by this method can be used in the actual high-density and high-power charge and discharge process (average current density ≥ 100mA / cm 2 , average power density ≥130mW / cm 2 ), the vanadium ion utilization rate is maintained at above 75%, thereby greatly improving the energy density of the electrolyte at the same molar concentration. The energy density of each mole of total vanadium ions can be increased from 8.0-13.0Wh / L of traditional electrolyte to 13.0-16.5Wh / L, thereby reducing the unit watt-hour cost of all-vanadium liquid flow batteries by 10-20%, which is conducive to the large-scale promotion and application of vanadium batteries.

[0011] 2. Significantly improve the capacity retention and stability of all-vanadium flow batteries: The electrolyte prepared by this method, under the synergistic effect of additives and high-valent vanadium ions (average valence of 3.51-3.69), can maintain high capacity and stability in the actual high-density and high-power charge and discharge process (average current density ≥100mA / cm 2 , average power density ≥130mW / cm 2 ), after more than 300 full charge and discharge tests, the capacity retention rate is ≥80%, which is about 10% higher than that of traditional electrolytes. And through deep discharge and positive and negative electrode mixing, the capacity retention rate of the electrolyte after long-term charge and discharge can be restored to more than 95%.

[0012] 3. Rich product variety and safety: This process sets up process chain A and process chain B for mixed operation, so that two products with different vanadium ion concentrations are produced in one process to meet market needs; process chain A can produce traditional high-purity electrolytes with an average vanadium ion valence of 3.5 without additives, and at the same time, the entire process can finally produce electrolytes with high vanadium ion valence (average valence of 3.51-3.69) of different concentrations with high activity, high vanadium ion utilization rate and high energy density. On the other hand, in order to avoid additives affecting the electrolysis effect and life of the electrolytic equipment. The B process chain in this scheme does not use electrolytic equipment, but adjusts the valence by mixing with the final product of process chain A, ensuring the safety of the electrolytic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work. In the drawings:

[0014] Figure 1 is a process flow chart of the present invention; DETAILED DESCRIPTION

[0015] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0016] Example 1

[0017] The present invention provides a process for preparing a vanadium battery electrolyte. Figure 1 As shown, including:

[0018] The average valence of vanadium ions is 3.5 (expressed as V 3.5+ ) of electrolyte A; the specific steps are as follows:

[0019] a. Feeding reaction section: The order of feeding in the feeding reaction is pure water → sulfuric acid → oxalic acid dihydrate → vanadium pentoxide, and the purity of all added substances must reach the standard of superior purity or analytical purity. The mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 2.64:0.70:1.

[0020] Specifically, start the pure water pump, add pure water into the glass-lined reactor, the conductivity of the pure water is not higher than 2us / cm, start the glass-lined reactor stirrer, and add 105.11L of 98% sulfuric acid at a uniform speed during stirring (calculated by the mass of sulfuric acid / 1.831 (density of sulfuric acid)), flush the pipeline with pure water 3 times after adding sulfuric acid, and the flushing water can be injected into the reactor again for work (the total volume of pure water finally added is 294.89L), and then add 51.03Kg of 99.6% oxalic acid dihydrate at a uniform speed during stirring, turn on the heating device of the glass-lined reactor, slowly heat the reaction liquid to 80-110°C and stabilize it in this temperature range, and the heating time is controlled within 60min.

[0021] Then continue stirring and reacting for 120-240 minutes, then slowly add 72.90 kg of vanadium pentoxide powder, the total feeding time is controlled to be 480-960 minutes, and the entire reaction temperature is controlled at 80-110 ° C. After adding the materials, keep warm, the insulation temperature is controlled at 80-95 ° C, and the insulation time is 5-8 hours. Then cool down, and the electrolyte temperature drops to 40-60 ° C to start filtering. The main equation of the entire reaction is V2O5+H2C2O4+2H2SO4→2VOSO4+2CO2↑+3H2O.

[0022] Since a large amount of gas is produced, the reaction speed needs to be controlled. Carbon dioxide and a small amount of acid mist will be released during the feeding process. At this time, the recovery device is started to recover the acid mist.

[0023] b. Filtration section: Use bag filter to filter the initial electrolyte. The filter mesh is ≥20000 mesh. The electrolyte is completely filtered through the bag filter equipment. The filter cloth or filter membrane used for filtration has a pore size of no more than 5μm and is made of strong acid resistant material. The electrolyte temperature in the filtration section is controlled at 30-50℃. The specific operation method is carried out according to the requirements of the bag filter.

[0024] c. Valence adjustment section: The filtered electrolyte is sent to the electrolysis equipment (electrolyte valence adjustment device) to adjust the average valence of the electrolyte vanadium ions to 3.5. The specific operation method is carried out according to the requirements of the electrolyte valence adjustment device, and finally the electrolyte A liquid with an average valence of vanadium ions of 3.5 is obtained, and the total volume of the final electrolyte A liquid is 400L (considering the molecular gap between liquids and solids, the total volume here is the sum of the volumes of sulfuric acid and pure water added), and the total vanadium ion concentration is 2.0mol / L.

[0025] The final high-purity electrolyte A solution containing no additives and having an average valence of 3.5 vanadium ions can be directly made into product A1 to meet the needs of the market.

[0026] In addition, liquid B with an average valence of 4.0 activated vanadium ions is prepared by first adding materials for reaction, stirring and controlling the temperature, then filtering, and finally activating to obtain liquid B.

[0027] The specific operation is as follows:

[0028] 1) The order of adding materials in the adding reaction is pure water → sulfuric acid → No. 1 additive → dihydrated oxalic acid → No. 2 additive → vanadium pentoxide, and the purity of all added materials must reach the standard of superior purity or analytical purity. The mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 2.64:0.70:1.

[0029] Specifically, the amount of pure water added is 51.61 L, the amount of 98% sulfuric acid added is 18.39 L, and the final volume of the configurable electrolyte is 70 L. The specific operation is the same as step a.

[0030] After adding sulfuric acid, slowly add additive No. 1 to the reactor, wherein additive No. 1 is a mixture of ascorbic acid and citric acid in a mass ratio of 1:1, and the addition amount of additive No. 1 is 0.1-5 g / L. In this embodiment, additive No. 1 is 0.1 g / L (the volume of the electrolyte is 70 L, that is, 0.1 g of additive No. 1 is added per liter of electrolyte), and the total amount of additive No. 1 added is 7 g, the feeding time is controlled at 10-30 min, and the temperature is controlled at 80-110 ° C.

[0031] After adding additive No. 1, continue stirring for 30 minutes and then add 8.93 kg of 99.6% oxalic acid dihydrate at a constant speed.

[0032] Then, the No. 2 additive is slowly added into the reactor, the No. 2 additive is a mixture of metatitanic acid, titanium nitrate and citric acid chelated titanium in a mass ratio of 1:1:1, and the addition amount of the No. 2 additive is 0.01-0.3 g / L. The No. 2 additive of this embodiment is 0.01 g / L (the volume of the electrolyte is 70 L, that is, 0.01 g of the No. 2 additive is added per liter of the electrolyte), the total amount of the No. 2 additive added is 0.7 g, the feeding time is controlled within 10 min, and the entire adding process is controlled at 80-110° C.

[0033] After that, the reaction was continued with stirring for 60 minutes, and 12.76 kg of high-purity vanadium pentoxide powder was slowly added. The total feeding time was controlled to be 960-1440 minutes, and the entire reaction temperature was controlled to be 80-110°C. The insulation time was 5-8 hours. After that, the temperature was lowered, and the electrolyte temperature dropped to 40-60°C before filtering.

[0034] Similar to step a, the reaction rate needs to be controlled because of the large amount of gas produced. Carbon dioxide and a small amount of acid mist will be released during the feeding process, and the recovery device is started to recover the acid mist.

[0035] The role and effect of adding additive No. 1 in the feeding reaction:

[0036] ① Improve the stability of the electrolyte: Ascorbic acid has reducing properties and can act as an antioxidant, which helps prevent the vanadium ions in the electrolyte from being oxidized at high potentials, thereby improving the stability of the electrolyte.

[0037] ② Improve electrochemical performance: Citric acid and its derivatives can form stable complexes with vanadium ions, which may help improve the electrochemical properties of the electrolyte, including increasing conductivity and electrochemical window.

[0038] ③ Inhibition of oxygen evolution side reaction: Due to its reducing property, ascorbic acid may help inhibit the oxygen evolution reaction of the electrolyte at a higher potential, which helps to improve the charge and discharge efficiency and cycle stability of the battery.

[0039] Effects and functions of adding additive No. 2:

[0040] ① Titanic acid (β-titanic acid) and titanium nitrate can enhance the conductivity. Adding them to the electrode can improve the conductive network of the electrode, make it easier for electrons to be transmitted in the electrode, reduce the resistance of the electrode, and improve the charge and discharge efficiency and power performance of the battery.

[0041] ② Increase the specific surface area: Titanic acid and titanium nitrate have a larger specific surface area, which can provide more active sites for electrochemical reactions. This means that more vanadium ions can participate in the redox reaction, thereby increasing the battery's energy storage capacity and reaction rate.

[0042] ③ Improve battery stability: β-titanic acid is a three-dimensional network structure formed by connecting TiO6 octahedrons through common vertices or common edges, which enhances the mechanical strength and structural stability of the electrode to a certain extent, enabling it to maintain a good shape and performance during long-term charge and discharge cycles, reduce the powdering and peeling of electrode materials, and extend the service life of the battery.

[0043] ④ Chemical stability: Titanic acid and titanium nitrate have good chemical stability and can resist the erosion of the electrolyte and some side reactions that may occur during the charging and discharging process, reduce the chemical attenuation of the electrode material, and further improve the stability and cycle life of the battery.

[0044] 2) The filtration section is the same as step b

[0045] 3) Activation stage

[0046] The electrolyte produced in step 2) above is pumped into an activation reactor, and additives No. 3 and No. 4 are added in sequence, and the stirring paddle is started to stir at a constant speed during the addition process to obtain activated B1 liquid. Specifically, the addition amount of additive No. 3 is 20-80 ml / L, and the addition amount of additive No. 4 is 5-50 g / L.

[0047] The preparation of additive No. 3 is as follows: add 80L of pure water to a 100L plastic reactor, then add sodium hydroxide (NaOH), lithium hydroxide (LiOH), cresol (C6H5CH3OH) and additives. The specific process is as follows: add analytically pure sodium hydroxide or lithium hydroxide to a beaker, with a total amount of NaOH and LiOH of 50-250g, heat the solution to 80-90°C, then slowly add 99% by mass cresol liquid under stirring conditions, with the amount of cresol added being 200-1000ml to ensure an excess of cresol, and continue stirring until the solid matter is completely dissolved. Finally, add water to dilute to 4000mL. The main reaction equation can be expressed as:

[0048] C6H5CH3OH+NaOH→C6H5CH3ONa(sodium cresol)+H2O

[0049] C6H5CH3OH+LiOH→C6H5CH3OLi(lithium cresol)+H2O

[0050] The auxiliary agent is 99.5% by mass of glacial acetic acid (CH3COOH) or 99% by mass of formic acid (HCOOH) or a mixture of the two. After preparation, cresol solution still exists in the No. 3 additive, and the amount of the auxiliary agent added is 300-800 ml.

[0051] In this embodiment, additive No. 3 includes cresol and sodium cresol, wherein 200 ml of cresol, 40 g of sodium hydroxide and 300 ml of an auxiliary agent are added, wherein the volume ratio of analytically pure glacial acetic acid to formic acid in the auxiliary agent is 1:1.

[0052] According to the above configuration, the amount of additive No. 3 added is 20 ml / L (i.e., 20 ml of additive No. 3 is added per liter of liquid volume), that is, the total amount of additive No. 3 added in this embodiment is 1.4 L. The electrolyte temperature in the activation reactor is about 20°C-50°C, and the electrolyte needs to be stirred at a uniform speed during the addition process. After adding additive No. 3, continue stirring for 1 hour and then start adding additive No. 4.

[0053] In this embodiment, additive No. 4 includes a mixture of lactose and cellobiose in a mass ratio of 1:1, and the amount of additive No. 4 added is 5g / L (the volume of the electrolyte is 70L, and 5g of additive No. 4 is added per liter of electrolyte), that is, the amount of additive No. 4 added is 0.35Kg. The electrolyte temperature in the activation reactor is about 20℃-50℃. After adding additive No. 4, continue stirring for 1h before starting to add and enter the mixing process.

[0054] Effects and functions of adding No. 3 additive:

[0055] ① Improve the conductivity of the electrolyte. Sodium cresol and lithium cresol can dissociate into sodium ions, lithium ions and corresponding organic anions in the electrolyte. The presence of these ions can increase the carrier concentration in the electrolyte, thereby improving the conductivity of the electrolyte, making it easier for charges to be transmitted inside the battery, helping to reduce the internal resistance of the battery and improve the charging and discharging efficiency of the battery.

[0056] ② Improve electrode reaction kinetics: Sodium cresol, lithium cresol and cresol participate in the reaction or adsorption process on the electrode surface, which plays a certain role in modifying the electrode surface, reducing the activation energy of the electrode reaction, promoting the charge transfer between the electrode and the electrolyte, making the battery's charging and discharging process smoother, and thus improving the battery's performance.

[0057] ③ Complexation or coordination: The hydroxyl and other functional groups in the cresol molecule have a certain degree of complexation or coordination with vanadium ions or other electrolyte components. This interaction helps to improve the stability of the electrolyte, which in turn has a positive impact on the performance of the battery. In addition, cresol also acts as a dispersant, reducing the surface energy of the particles and inhibiting the coagulation of the colloid particles, which helps to prevent the precipitation of the electrolyte at high temperatures and improve the operating efficiency and life of the battery.

[0058] Effects and functions of adding No. 4 additive:

[0059] ① Effectively inhibit the capacity decay of vanadium batteries. Adding lactose and cellobiose additives can provide additional osmotic pressure to reduce the osmotic pressure difference between the electrolytes on both sides during the cycle, thereby reducing the transmembrane migration of vanadium ions and slowing down capacity decay.

[0060] ② The second is to improve the performance of the electrolyte. Specifically, it improves the ionic conductivity of the electrolyte: lactose and cellobiose will ionize in water and produce hydrogen ions (H + ) and lactose anions. The presence of these ions can increase the carrier concentration in the electrolyte, thereby improving the conductivity of the electrolyte, making it easier to transfer charges inside the battery, helping to reduce the internal resistance of the battery and improve the battery's charge and discharge efficiency. Affects the electrode reaction kinetics. Interface interaction and reaction promotion: At the interface between the electrode and the electrolyte, the ions or molecules dissociated from lactose and cellobiose will interact with the electrode surface and adsorb on the electrode surface to form a specific adsorption layer. In addition, the hydroxyl functional groups (-OH) in lactose and cellobiose molecules have the ability to bind to vanadium ions to form a stable VO structure, and can be adsorbed on the electrode surface, providing more reactive sites for electrochemical reactions, thereby improving the performance of the negative electrode electrolyte. Lactose and cellobiose act as osmotic pressure regulators in the electrolyte. The addition of disaccharides such as lactose and cellobiose improves the performance and stability of vanadium batteries through both physical and chemical methods.

[0061] Then, in this embodiment, electrolyte A and electrolyte B are mixed according to a volume ratio V A :V B =1:0.18 ratio in a 500L liquid storage tank for full mixing, that is, adding 400L of 3.5-valent electrolyte prepared by chain A and 70L of activated electrolyte prepared by chain B into a mixing tank for stirring and mixing, and performing valence state analysis and valence state adjustment by the volume mixing ratio of liquid A and liquid B. It has been found through experiments that the adjustment of valence state can improve the activity of vanadium ions and ultimately improve the performance of the electrolyte.

[0062] During the process, the valence state is adjusted by mixing the liquid. Since most of the additives are organic matter, they will affect the electrolysis effect of the electrolysis equipment, so the electrolysis equipment is not used in the process.

[0063] This process sets up process chain A and process chain B for mixed operation, so that more than two products can be produced in one process to meet market needs, and on the other hand, avoid conflicts between additives and electrolytic equipment. The adjustment range of the average valence of vanadium ions in the electrolyte is: 3.51-3.69, which can be obtained by calculation. The specific calculation formula is: Assume that V3 in the electrolyte + and V4 + The concentrations of C1 and C2 are respectively, then the average valence state of the vanadium electrolyte can be calculated by the following formula: Average valence state of the vanadium electrolyte = (3*C1+4*C2) / (C1+C2).

[0064] Configure high-valent vanadium ions (V 3.51+～3.69+ ) electrolyte can effectively improve the stability of the electrolyte: in the vanadium battery electrolyte, due to V 2+ The accumulation of unusable V2+ on the negative electrode side caused by transmembrane transport causes vanadium battery valence imbalance and rapid capacity decay. 3.51+～3.69+ ), excessive VO will be generated in the cathode solution 2+ On the one hand, it can avoid the unusable V 2+ On the other hand, the accumulation on the negative electrode side will also enhance the convection transmission between the positive and negative electrode electrolytes, so that the electrolytes on both sides can quickly reach a stable state of diffusion and convection, thereby achieving higher battery efficiency and discharge capacity.

[0065] In addition, the mixing volume ratio of liquid A and liquid B differs by about 10 times. If the process of preparing liquid A is omitted, the amount of additives used will be greater under the same total volume. However, this solution only needs to consider the volume in liquid B, which reduces the amount of additives used and saves costs.

[0066] After the addition of acid and sulfuric acid is completed, the mixture is stirred for 12-24 hours and then pumped into an activated electrolyte storage tank for storage for 3-5 days to produce the finished product AB1. In this embodiment, the average valence of vanadium ions in the AB1 electrolyte is 3.57.

[0067] Example 2

[0068] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A2 is as follows: 3509.29L of pure water, 490.71L of 98% sulfuric acid, the total volume of the electrolyte is 4000L, 464.7Kg of 99.6% oxalic acid dihydrate, 619.65Kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 1.45:0.75:1. The final product A2 (V 3.5+ ).

[0069] The process of preparing activated B liquid is as follows: add 70.19L of pure water, 9.81L of 98% sulfuric acid, that is, the total volume of the electrolyte is 80L, the No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 1:9, the amount of the No. 1 additive is 40g (the total volume of the electrolyte is 80L, and the amount of the No. 1 additive per liter of the electrolyte is 0.5g), 9.91Kg of 99.6% oxalic acid dihydrate, and the No. 2 additive is a mixture of citric acid and ascorbic acid in a mass ratio of 8:1:1. A mixture of titanic acid, titanium nitrate and citric acid chelated titanium, with a total addition amount of 4g (the total volume of the electrolyte is 80L, and the addition amount of additive No. 2 per liter of electrolyte is 0.05g), 99.8% vanadium pentoxide powder 12.39Kg, in this embodiment, additive No. 3 includes cresol and sodium cresol, wherein 300ml of cresol, 50g of sodium hydroxide and 400ml of an auxiliary agent are added, and the volume ratio of analytically pure glacial acetic acid to formic acid in the auxiliary agent is 6:4. The total amount of additive No. 3 added is 3.2L (the total volume of the electrolyte is 80L, and the amount of additive No. 3 added per liter of electrolyte is 40ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose in a mass ratio of 1:1, and the total amount of additive No. 4 added is 0.8Kg (the total volume of the electrolyte is 80L, and the amount of additive No. 4 added per liter of electrolyte is 10g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 1.45:0.8:1, and the activated B2 solution (V 4.0+ ).

[0070] The electrolyte A2 and the activated B2 solution are mixed at a volume ratio of 1:0.02. The final vanadium ion concentration is 1.7 mol / L, the average valence of the vanadium ions is 3.51, and the finished product AB2 is finally obtained.

[0071] Example 3

[0072] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A3 is as follows: 3074.33 L of pure water, 925.67 L of 98% sulfuric acid, the total volume of the electrolyte is 4000 L, 677.96 kg of 99.6% oxalic acid dihydrate, and 564.97 kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 3:1.2:1, and the finished product A3 (V 3.5+ ).

[0073] The process of preparing activated B liquid is as follows: adding 614.87L of pure water, 185.13L of 98% sulfuric acid, that is, the total volume of the electrolyte is 800L, the No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 8:2, the amount of the No. 1 additive is 1600g (the total volume of the electrolyte is 800L, and the amount of the No. 1 additive per liter of the electrolyte is 2g), 146.89Kg of 99.6% oxalic acid dihydrate, and the No. 2 additive is a mixture of titanic acid, nitric acid and sodium nitrate in a mass ratio of 4:3:3. A mixture of titanium chelate and titanium citric acid, with a total addition amount of 80g (the total volume of the electrolyte is 800L, and the addition amount of No. 2 additive per liter of electrolyte is 0.1g), 99.8% vanadium pentoxide powder 112.99Kg, in this embodiment No. 3 additive includes cresol, sodium cresol and lithium cresol, wherein 1000ml of cresol, 50g of sodium hydroxide, 50g of lithium hydroxide, and 500ml of an auxiliary agent are added, and the volume ratio of analytical pure glacial acetic acid to formic acid in the auxiliary agent is 3:7. The total amount of additive No. 3 added is 48L (the total volume of the electrolyte is 800L, and the amount of additive No. 3 added per liter of electrolyte is 60ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose in a mass ratio of 3:7, and the total amount of additive No. 4 added is 20Kg (the total volume of the electrolyte is 800L, and the amount of additive No. 4 added per liter of electrolyte is 25g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 3:1.3:1, and the activated B3 solution (V 4.0+ ).

[0074] The electrolyte A3 and the activated B3 solution were mixed at a volume ratio of 1:0.2. The final vanadium ion concentration was 1.55 mol / L, the average valence of the vanadium ions was 3.58, and the finished product AB3 was finally obtained.

[0075] Example 4

[0076] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A4 is as follows: adding 2885.21L of pure water, 1114.79L of 98% sulfuric acid, and the total volume of the electrolyte is 4000L, 816.47Kg of 99.6% oxalic acid dihydrate, and 583.20Kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 3.5:1.4:1, and finally obtaining the finished product A4 (V 3.5+ ).

[0077] The process of preparing activated B liquid is as follows: adding 865.56L of pure water, 334.44L of 98% sulfuric acid, that is, the total volume of the electrolyte is 1200L, No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 3:7, the amount of No. 1 additive added is 3600g (the total volume of the electrolyte is 1200L, and the amount of No. 1 additive added per liter of electrolyte is 3g), 262.44Kg of 99.6% oxalic acid dihydrate, and No. 2 additive is a mixture of titanic acid, nitric acid and sodium nitrate in a mass ratio of 2:2:6. A mixture of titanium chelate and titanium citric acid, with a total addition amount of 240g (the total volume of the electrolyte is 1200L, and the addition amount of No. 2 additive per liter of electrolyte is 0.2g), 99.8% vanadium pentoxide powder 174.96Kg, in this embodiment No. 3 additive includes cresol, sodium cresol and lithium cresol, wherein 300ml of cresol is added, 50g of sodium hydroxide is added, 200g of lithium hydroxide is added, and 500ml of an auxiliary agent is added, and the volume ratio of analytical pure glacial acetic acid to formic acid in the auxiliary agent is 2:8 for configuration. The total amount of additive No. 3 added is 96L (the total volume of the electrolyte is 1200L, and the amount of additive No. 3 added per liter of electrolyte is 80ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose in a mass ratio of 2:8, and the total amount of additive No. 4 added is 60Kg (the total volume of the electrolyte is 1200L, and the amount of additive No. 4 added per liter of electrolyte is 50g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 3.5:1.5:1, and the activated B4 solution (V 4.0+ ).

[0078] The electrolyte A4 and the activated B4 solution were mixed at a volume ratio of 1:0.3. The final vanadium ion concentration was 1.6 mol / L, the average valence of the vanadium ions was 3.62, and the finished product AB4 was finally obtained.

[0079] Example 5

[0080] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A5 is as follows: 2972.80 L of pure water, 1027.20 L of 98% sulfuric acid, the total volume of the electrolyte is 4000 L, 626.94 Kg of 99.6% oxalic acid dihydrate, and 626.94 Kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 3:1:1, and the finished product A5 (V 3.5+ ).

[0081] The process of preparing activated B liquid is as follows: adding 743.20L of pure water, 256.80L of 98% sulfuric acid, that is, the total volume of the electrolyte is 1000L, the No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 7:3, the amount of the No. 1 additive added is 5000g (the total volume of the electrolyte is 1000L, and the amount of the No. 1 additive added per liter of the electrolyte is 5g), 250.77Kg of 99.6% oxalic acid dihydrate, and the No. 2 additive is a mixture of titanic acid and nitric acid in a mass ratio of 4:4:2. A mixture of titanium and citric acid chelated titanium, with a total addition amount of 300g (the total volume of the electrolyte is 1000L, and the addition amount of No. 2 additive per liter of electrolyte is 0.3g), 99.8% vanadium pentoxide powder 156.73Kg, in this embodiment No. 3 additive includes cresol, sodium cresol and lithium cresol, wherein 400ml of cresol, 100g of sodium hydroxide, 50g of lithium hydroxide, and 600ml of auxiliary agent are added, and the volume ratio of analytical pure glacial acetic acid to formic acid in the auxiliary agent is 1:9 for configuration. The total amount of additive No. 3 added is 70L (the total volume of the electrolyte is 1000L, and the amount of additive No. 3 added per liter of electrolyte is 70ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose with a mass ratio of 1.5:8.5, and the total amount of additive No. 4 added is 40Kg (the total volume of the electrolyte is 1000L, and the amount of additive No. 4 added per liter of electrolyte is 40g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 3:1.6:1, and the activated B5 solution (V 4.0+ ).

[0082] The electrolyte A5 and the activated B5 solution were mixed at a volume ratio of 1:0.25. The final vanadium ion concentration was 1.72 mol / L, the average valence of the vanadium ions was 3.60, and the finished product AB5 was finally obtained.

[0083] Example 6

[0084] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A6 is as follows: 3129.07 L of pure water, 870.93 L of 98% sulfuric acid, the total volume of the electrolyte is 4000 L, 574.08 kg of 99.6% oxalic acid dihydrate, and 637.87 kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 2.5:0.9:1, and the finished product A6 (V 3.5+ ).

[0085] The process of preparing activated B liquid is as follows: adding 625.81L of pure water, 174.19L of 98% sulfuric acid, that is, the total volume of the electrolyte is 800L, the No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 4:6, the amount of the No. 1 additive added is 3200g (the total volume of the electrolyte is 800L, and the amount of the No. 1 additive added per liter of the electrolyte is 4g), 114.82Kg of 99.6% oxalic acid dihydrate, and the No. 2 additive is a mixture of metatitanic acid, titanium nitrate and citric acid in a mass ratio of 1:2:7. A mixture of citric acid chelated titanium, with a total addition amount of 120g (the total volume of the electrolyte is 800L, and the addition amount of No. 2 additive per liter of electrolyte is 0.15g), 99.8% vanadium pentoxide powder 127.57Kg, in this embodiment No. 3 additive includes cresol, sodium cresol and lithium cresol, wherein 120ml of cresol, 100g of sodium hydroxide, 150g of lithium hydroxide, and 700ml of auxiliary agent are added, and the volume ratio of analytical pure glacial acetic acid to formic acid in the auxiliary agent is 1.5:8.5 for configuration. The total amount of additive No. 3 added is 40L (the total volume of the electrolyte is 800L, and the amount of additive No. 3 added per liter of electrolyte is 50ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose in a mass ratio of 4:6, and the total amount of additive No. 4 added is 24Kg (the total volume of the electrolyte is 800L, and the amount of additive No. 4 added per liter of electrolyte is 30g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 2.5:0.9:1, and the activated B6 solution (V 4.0+ ).

[0086] The electrolyte A6 and the activated B6 solution were mixed at a volume ratio of 1:0.2. The final vanadium ion concentration was 1.75 mol / L, the average valence of the vanadium ions was 3.58, and the finished product AB6 was finally obtained.

[0087] Example 7

[0088] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A7 is as follows: 328.34 L of pure water, 71.66 L of 98% sulfuric acid, the total volume of the electrolyte is 400 L, 52.49 kg of 99.6% oxalic acid dihydrate, and 65.61 kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 2.0:0.8:1, and the finished product A7 (V 3.5+ ).

[0089] The process of preparing activated B liquid is as follows: add 82.38L of pure water, 37.62L of 98% sulfuric acid, that is, the total volume of the electrolyte is 120L, additive No. 1 is a mixture of ascorbic acid and citric acid in a mass ratio of 3.5:6.5, the amount of additive No. 1 added is 120g (the total volume of the electrolyte is 120L, and the amount of additive No. 1 added per liter of electrolyte is 1g), 15.75Kg of 99.6% dihydrate oxalic acid, and additive No. 2 is a mixture in a mass ratio of 1:1.5:7 .5 mixture of titanic acid, titanium nitrate and citric acid chelated titanium, with a total addition amount of 30g (the total volume of the electrolyte is 120L, and the addition amount of additive No. 2 per liter of electrolyte is 0.25g), 99.8% vanadium pentoxide powder 19.68Kg, in this embodiment, additive No. 3 includes cresol and cresol lithium, of which 1000ml of cresol, 250g of lithium hydroxide, and 550ml of auxiliary agent are added, and the volume ratio of analytical pure glacial acetic acid to formic acid in the auxiliary agent is 4:6. The total amount of additive No. 3 added is 3.6L (the total volume of the electrolyte is 120L, and the amount of additive No. 3 added per liter of electrolyte is 30ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose in a mass ratio of 7:3, and the total amount of additive No. 4 added is 2.4Kg (the total volume of the electrolyte is 120L, and the amount of additive No. 4 added per liter of electrolyte is 20g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 2.0:0.8:1, and the activated B7 solution (V 4.0+ ).

[0090] The electrolyte A7 and the activated B7 solution were mixed at a volume ratio of 1:0.3. The final vanadium ion concentration was 1.80 mol / L, the average valence of the vanadium ions was 3.62, and the finished product AB7 was finally obtained.

[0091] Example 8

[0092] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A8 is as follows: 333.710L of pure water, 66.29L of 98% sulfuric acid, the total volume of the electrolyte is 400L, 43.83Kg of 99.6% oxalic acid dihydrate, and 67.43Kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 1.8:0.65:1, and the finished product A8 (V 3.5+ ).

[0093] The process of preparing activated B liquid is as follows: adding 200.23L of pure water, 39.77L of 98% sulfuric acid, that is, the total volume of the electrolyte is 240L, the No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 2:8, the amount of the No. 1 additive added is 192g (the total volume of the electrolyte is 240L, and the amount of the No. 1 additive added per liter of the electrolyte is 0.8g), 26.30Kg of 99.6% dihydrated oxalic acid, the No. 2 additive is a mixture of titanic acid in a mass ratio of 3:4:3, A mixture of titanium nitrate and citric acid chelated titanium, with a total addition amount of 12g (the total volume of the electrolyte is 240L, and the addition amount of No. 2 additive per liter of electrolyte is 0.05g), 99.8% vanadium pentoxide powder 40.46Kg, in this embodiment, No. 3 additive includes cresol and sodium cresol, wherein 350ml of cresol, 25g of sodium hydroxide, 25g of lithium hydroxide, and 800ml of an auxiliary agent are added, and the volume ratio of analytically pure glacial acetic acid to formic acid in the auxiliary agent is 7:3. The total amount of additive No. 3 added is 8.4L (the total volume of the electrolyte is 240L, and the amount of additive No. 3 added per liter of electrolyte is 35ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose with a mass ratio of 5.5:4.5, and the total amount of additive No. 4 added is 8.4Kg (the total volume of the electrolyte is 240L, and the amount of additive No. 4 added per liter of electrolyte is 35g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 1.8:0.65:1, and the activated B8 solution (V 4.0+ ).

[0094] The electrolyte A8 and the activated B8 solution were mixed at a volume ratio of 1:0.6. The final vanadium ion concentration was 1.85 mol / L, the average valence of the vanadium ions was 3.69, and the finished product AB8 was finally obtained.

[0095] Example 9

[0096] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A9 is as follows: 288.52L of pure water, 111.48L of 98% sulfuric acid, the total volume of the electrolyte is 400L, 80.19Kg of 99.6% oxalic acid dihydrate, 72.90Kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 2.8:1.1:1, and the finished product A9 (V 3.5+ ).

[0097] The process of preparing activated B liquid is as follows: add 57.70L of pure water, 22.30L of 98% sulfuric acid, that is, the total volume of the electrolyte is 80L, additive No. 1 is a mixture of ascorbic acid and citric acid in a mass ratio of 4.5:5.5, the amount of additive No. 1 added is 32g (the total volume of the electrolyte is 80L, and the amount of additive No. 1 added per liter of electrolyte is 0.4g), 16.04Kg of 99.6% dihydrate oxalic acid, and additive No. 2 is a mixture of ascorbic acid and citric acid in a mass ratio of 3:3:4 A mixture of titanic acid, titanium nitrate and citric acid chelated titanium, with a total addition amount of 2.4g (the total volume of the electrolyte is 80L, and the addition amount of additive No. 2 per liter of electrolyte is 0.03g), 99.8% vanadium pentoxide powder 14.58Kg, in this embodiment, additive No. 3 includes cresol and sodium cresol, wherein 800ml of cresol, 250g of sodium hydroxide, and 450ml of an auxiliary agent are added, and the volume ratio of analytical pure glacial acetic acid to formic acid in the auxiliary agent is 8:2. The total amount of additive No. 3 added is 3.6L (the total volume of the electrolyte is 80L, and the amount of additive No. 3 added per liter of electrolyte is 45ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose in a mass ratio of 8:2, and the total amount of additive No. 4 added is 3.6Kg (the total volume of the electrolyte is 80L, and the amount of additive No. 4 added per liter of electrolyte is 45g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 2.8:1.1:1, and the activated B9 solution (V 4.0+ ).

[0098] The electrolyte A9 and the activated B9 solution were mixed at a volume ratio of 1:0.2. The final vanadium ion concentration was 2.00 mol / L, the average valence of the vanadium ions was 3.58, and the finished product AB9 was finally obtained.

[0099] Example 10

[0100] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A10 is as follows: 275.78 L of pure water, 124.22 L of 98% sulfuric acid, the total volume of the electrolyte is 400 L, 63.97 kg of 99.6% oxalic acid dihydrate, 71.08 kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 3.2:0.9:1, and the finished product A10 (V3.5+ ).

[0101] The process of preparing activated B liquid is as follows: adding 62.05L of pure water, 27.95L of 98% sulfuric acid, that is, the total volume of the electrolyte is 90L, the No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 6:4, the amount of the No. 1 additive added is 135g (the total volume of the electrolyte is 90L, and the amount of the No. 1 additive added per liter of the electrolyte is 1.5g), 17.59Kg of 99.6% oxalic acid dihydrate, and the No. 2 additive is a mixture of metatitanic acid, titanium nitrate and A mixture of citric acid chelated titanium, with a total addition amount of 20.7g (the total volume of the electrolyte is 90L, and the addition amount of No. 2 additive per liter of electrolyte is 0.23g), 99.8% vanadium pentoxide powder 15.99Kg, and No. 3 additive in this embodiment includes cresol, sodium cresol and lithium cresol, wherein 280ml of cresol, 175g of sodium hydroxide, 75g of lithium hydroxide, and 650ml of an auxiliary agent are added, and the volume ratio of analytically pure glacial acetic acid to formic acid in the auxiliary agent is 9:1 for configuration. The total amount of additive No. 3 added is 4.95L (the total volume of the electrolyte is 90L, and the amount of additive No. 3 added per liter of electrolyte is 55ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose with a mass ratio of 9:1, and the total amount of additive No. 4 added is 1.35Kg (the total volume of the electrolyte is 90L, and the amount of additive No. 4 added per liter of electrolyte is 15g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 3.2:1.1:1, and the activated B10 solution (V 4.0+ ).

[0102] The electrolyte A10 and the activated B10 solution were mixed at a volume ratio of 1:0.23. The final vanadium ion concentration was 1.95 mol / L, the average valence of the vanadium ions was 3.59, and the finished product AB10 was finally obtained.

[0103] Embodiment 11

[0104] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A11 is as follows: 325.35 L of pure water, 74.65 L of 98% sulfuric acid, the total volume of the electrolyte is 400 L, 109.35 kg of 99.6% oxalic acid dihydrate, 91.12 kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 1.5:1.2:1, and the finished product A11 (V 3.5+ ).

[0105] The process of preparing activated B liquid is as follows: adding 97.60L of pure water, 22.40L of 98% sulfuric acid, that is, the total volume of the electrolyte is 120L, the No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 9:1, the amount of the No. 1 additive added is 540g (the total volume of the electrolyte is 120L, and the amount of the No. 1 additive added per liter of the electrolyte is 4.5g), 32.81Kg of 99.6% oxalic acid dihydrate, and the No. 2 additive is a mixture of metatitanic acid, titanium nitrate and citric acid in a mass ratio of 3:2:5. A mixture of acid-chelated titanium, with a total addition amount of 33.6 g (the total volume of the electrolyte is 120 L, and the addition amount of No. 2 additive per liter of electrolyte is 0.28 g), 99.8% vanadium pentoxide powder 27.34 kg, in this embodiment, No. 3 additive includes cresol, sodium cresol and lithium cresol, wherein 280 ml of cresol, 100 g of sodium hydroxide, 50 g of lithium hydroxide, and 280 ml of an auxiliary agent are added, and the volume ratio of analytically pure glacial acetic acid to formic acid in the auxiliary agent is 2.5:7.5 for configuration. The total amount of additive No. 3 added is 3.0L (the total volume of the electrolyte is 120L, and the amount of additive No. 3 added per liter of electrolyte is 25ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose with a mass ratio of 3.5:6.5, and the total amount of additive No. 4 added is 4.2Kg (the total volume of the electrolyte is 120L, and the amount of additive No. 4 added per liter of electrolyte is 35g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 1.5:1.2:1, and the activated B11 solution (V 4.0+ ).

[0106] The electrolyte A11 and the activated B11 solution are mixed at a volume ratio of 1:0.3, the final vanadium ion concentration is 2.5 mol / L, the final electrolyte vanadium ion valence is 3.62, and the finished product AB11 is finally obtained.

[0107] Example 12

[0108] The process steps of this embodiment are the same as those of embodiment 1, except that: the process of preparing electrolyte A12 is as follows: 3087.86L of pure water, 912.14L of 98% sulfuric acid, the total volume of the electrolyte is 4000L, 575.91Kg of 99.6% oxalic acid dihydrate, and 575.91Kg of 99.8% vanadium pentoxide powder, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate and vanadium pentoxide is 2.9:1:1, and finally the finished product A12 (V 3.5+ ).

[0109] The process of preparing activated B liquid is as follows: adding 617.57L of pure water, 182.43L of 98% sulfuric acid, that is, the total volume of the electrolyte is 800L, No. 1 additive is a mixture of ascorbic acid and citric acid in a mass ratio of 6.5:3.5, the amount of No. 1 additive added is 4000g (the total volume of the electrolyte is 800L, and the amount of No. 1 additive added per liter of electrolyte is 5g), 115.18Kg of 99.6% oxalic acid dihydrate, No. 2 additive is a mixture of metatitanic acid, titanium nitrate and A mixture of citric acid chelated titanium, with a total addition amount of 96g (the total volume of the electrolyte is 800L, and the addition amount of additive No. 2 per liter of electrolyte is 0.12g), 99.8% vanadium pentoxide powder 115.18Kg, in this embodiment, additive No. 3 includes cresol, sodium cresol and lithium cresol, wherein 175ml of cresol, 145g of sodium hydroxide, 105g of lithium hydroxide, and 750ml of an auxiliary agent are added, and the analytically pure glacial acetic acid and formic acid in the auxiliary agent are configured according to a volume ratio of 4.5:5.5. The total amount of additive No. 3 added is 28L (the total volume of the electrolyte is 800L, and the amount of additive No. 3 added per liter of electrolyte is 35ml), and the total amount of additive No. 4 is a mixture of lactose and cellobiose with a mass ratio of 2.5:7.5, and the total amount of additive No. 4 added is 20Kg (the total volume of the electrolyte is 800L, and the amount of additive No. 4 added per liter of electrolyte is 25g), wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 2.9:1:1, and the activated B12 solution (V 4.0+ ).

[0110] The electrolyte A12 and the activated B12 solution are mixed at a volume ratio of 1:0.2. The final vanadium ion concentration is 1.58 mol / L, the final electrolyte vanadium ion valence is 3.58, and the finished product AB12 is finally obtained.

[0111] Embodiment 13

[0112] The process of preparing electrolyte A13 is the same as that of Example 3, and the finished product A13 (V 3.5+ ).

[0113] The process of preparing activated B solution is the same as that of Example 3, except that: No. 1 additive is added, and No. 3 additive includes cresol, sodium cresol and lithium cresol, wherein 200 ml of cresol, 200 g of sodium hydroxide, 50 g of lithium hydroxide and 500 ml of auxiliary agent are added, and the volume ratio of analytically pure glacial acetic acid to formic acid in the auxiliary agent is 3:7 to obtain activated B13 solution (V 4.0+ ).

[0114] The electrolyte A13 and the activated B13 solution were mixed at a volume ratio of 1:0.2. The final vanadium ion concentration was 1.55 mol / L, the average valence of the vanadium ions was 3.58, and the finished product AB13 was finally obtained.

[0115] Embodiment 14

[0116] The process of preparing electrolyte A14 is the same as that of Example 3, and the finished product A14 (V 3.5+ ).

[0117] The process of preparing activated liquid B is the same as that of Example 3, except that: No. 2 additive is added, and No. 3 additive includes cresol, sodium cresol and lithium cresol, wherein 200 ml of cresol, 200 g of sodium hydroxide, 50 g of lithium hydroxide and 500 ml of auxiliary agent are added, and the volume ratio of analytically pure glacial acetic acid to formic acid in the auxiliary agent is 3:7 to obtain activated liquid B14 (V 4.0+ ).

[0118] The electrolyte A14 and the activated B14 solution were mixed at a volume ratio of 1:0.2. The final vanadium ion concentration was 1.55 mol / L, the average valence of the vanadium ions was 3.58, and the finished product AB14 was finally obtained.

[0119] Embodiment 15

[0120] The process of preparing electrolyte A15 is the same as that of Example 3, and the finished product A15 (V 3.5+ ).

[0121] The process of preparing activated B solution is the same as that of Example 3, except that additive No. 3 is not added, and activated B15 solution is finally obtained.

[0122] The electrolyte A15 and the activated B15 solution were mixed at a volume ratio of 1:0.2, and the final vanadium ion concentration was 1.55 mol / L, and the average valence of the vanadium ion was 3.58. The finished product AB15 (V 4.0+ ).

[0123] Example 16

[0124] The process of preparing electrolyte A16 is the same as that of Example 3, and finally the finished product A16 (V 3.5+ ).

[0125] The process of preparing activated liquid B is the same as that of Example 3, except that: No. 4 additive is not added, and No. 3 additive includes cresol, sodium cresol and lithium cresol, wherein 200 ml of cresol, 200 g of sodium hydroxide, 50 g of lithium hydroxide and 500 ml of auxiliary agent are added, and the volume ratio of analytically pure glacial acetic acid to formic acid in the auxiliary agent is 3:7 to obtain activated liquid B16 (V 4.0+ ).

[0126] The electrolyte A16 and the activated B16 solution were mixed at a volume ratio of 1:0.2. The final vanadium ion concentration was 1.55 mol / L, the average valence of the vanadium ions was 3.58, and the finished product AB16 was finally obtained.

[0127] In summary, some electrical performance tests of the electrolytes of various embodiments are shown in Table 1 (the average current density of charge and discharge is ≥ 100 mA / cm 2 , average power density ≥130mW / cm 2 ).

[0128] Table 1 Some electrical performance test results

[0129]

[0130] It can be seen from Table 1 that in Examples 1-12, the initial energy density of the electrolyte after adding the additive and the 300 times

[0131] The capacity retention rate after charge and discharge is higher than that of the electrolyte without additives.

[0132] Compared with Example 3, No. 1 additive was not added in Example 13, No. 2 additive was not added in Example 14, No. 3 additive was not added in Example 15, and No. 4 additive was not added in Example 16. The capacity retention rate after 300 charge and discharge cycles was significantly lower than that of Example 3. From the above, it can be seen that the combined use of No. 1, No. 2, No. 3 and No. 4 additives can significantly increase the capacity retention rate of the electrolyte and ensure the stability of the electrolyte.

[0133] The performance tests of the energy efficiency, energy density and other performances of the electrolytes of various embodiments are shown in Table 2.

[0134] Table 2 Performance test results of electrolyte such as energy efficiency and energy density

[0135]

[0136]

[0137] As can be seen from Table 2, the final products AB1-AB12 have a vanadium ion utilization rate of more than 75% in the electrochemical reaction of the vanadium battery, reflecting the high activity of the electrolyte.

[0138] Compared with Example 3, No. 1 additive was not added in Example 13, No. 2 additive was not added in Example 14, No. 3 additive was not added in Example 15, and No. 4 additive was not added in Example 16. The average vanadium ion utilization rate after 300 charge and discharge, the average energy efficiency after 300 charge and discharge, and the energy density after 300 charge and discharge were all lower than those in Example 3. In summary, it can be seen that the combined use of No. 1, No. 2, No. 3 and No. 4 additives can significantly increase the average vanadium ion utilization rate after 300 charge and discharge, the average energy efficiency after 300 charge and discharge, and the energy density after 300 charge and discharge of the electrolyte.

[0139] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for preparing a vanadium battery electrolyte, characterized in that: Includes: preparing an electrolyte A solution in which the average valence of vanadium ions is 3.5; Preparation of liquid B with an average valence of vanadium ions of 4.0: firstly, a feed reaction is performed, during which additives No. 1 and No. 2 are added, stirring and temperature is controlled, and then filtering and activation are performed, during which additives No. 3 and No. 4 are added, and finally liquid B with an average valence of vanadium ions of 4.0 is obtained; Liquid A and liquid B are mixed to adjust the valence state, and an AB electrolyte having an average valence state of vanadium ions of 3.51 to 3.69 is prepared, and finally the electrolyte is placed for activation.

2. The process for preparing vanadium battery electrolyte according to claim 1, characterized in that: The preparation process of liquid A is as follows: pure water, sulfuric acid, oxalic acid dihydrate, and vanadium pentoxide are added to a reactor in sequence for addition reaction, wherein the mass ratio of sulfuric acid, oxalic acid dihydrate, and vanadium pentoxide is 1.45-3.5:0.65-1.40:1, the entire reaction needs to be carried out under stirring, the material temperature in the reactor is 80°C-128°C, and then 3.5-valent electrolyte liquid A is obtained through filtering and electrolysis operations.

3. The process for preparing vanadium battery electrolyte according to claim 1, characterized in that: The reaction process of adding materials is as follows: pure water, sulfuric acid, additive No. 1, dihydrated oxalic acid, additive No. 2 and vanadium pentoxide are added into the reaction kettle in sequence, and stirred during the adding process. The temperature is 80° C.-118° C., wherein the mass ratio of sulfuric acid, dihydrated oxalic acid and vanadium pentoxide is 1.45-3.5:0.70-1.60:

1.

4. The process for preparing vanadium battery electrolyte according to claim 3, characterized in that: The activation operation process is: slowly add No. 3 and No. 4 additives to the activation reaction kettle for activation, stirring during the addition process, and the temperature is 20°C-50°C.

5. The process for preparing vanadium battery electrolyte according to claim 1, characterized in that: The mixing volume ratio of the liquid A to the liquid B is 1:0.02-0.

6.

6. The process for preparing vanadium battery electrolyte according to claim 1, characterized in that: The additive No. 1 includes one or both of ascorbic acid and citric acid.

7. The process for preparing vanadium battery electrolyte according to claim 1, characterized in that: The No. 2 additive includes one or more of metatitanic acid, titanium nitrate, and citric acid chelated titanium.

8. The process for preparing vanadium battery electrolyte according to claim 1, characterized in that: The No. 3 additive includes one or more of cresol, lithium cresol and sodium cresol.

9. The process for preparing vanadium battery electrolyte according to claim 1, characterized in that: The additive No. 4 includes one or both of lactose and cellobiose.

10. The process for preparing vanadium battery electrolyte according to claim 1, characterized in that: The pore size of the filter cloth in the filtering operation does not exceed 5 μm.

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