312results about "Vanadium compounds" patented technology

The invention relates to the technical field of preparation of an electrolyte for a vanadium redox flow battery, in particular to a reduction method of an alkaline vanadium-containing solution during short-process preparation of a vanadium electrolyte. The reduction method comprises the following steps: (1) adding a reducing agent sodium sulfite into an alkaline vanadium-containing solution and dissolving; and (2) acid is added into the solution obtained after dissolving in the step (1), the pH is adjusted, a reduction reaction is conducted, and vanadium is reduced to be tetravalent. The method provided by the invention effectively solves the problem of vanadium loss caused by precipitation generated in the sequential operation process of acidification and reduction of the alkaline vanadium-containing solution in the prior art, and meanwhile, the method provided by the invention is easy for engineering implementation.

The invention discloses a silver vanadate photocatalytic material, a preparation method thereof and an illuminating lamp. The preparation method comprises the following steps: firstly, respectively dissolving NH4VO3 and AgNO3 in deionized water, uniformly mixing by magnetic stirring, adjusting the pH value of the solution, and then carrying out hydrothermal synthesis reaction to obtain the Ag3VO4 photocatalytic material. The Ag3VO4 photocatalytic material with controllable morphology, uniform particle size and good dispersity is prepared by adopting a synthesis strategy of a one-step hydrothermal method, the performance of the photocatalyst is optimized by regulating and controlling the pH value, the raw materials and the process are simple, the conditions are easy to control, the cost is low, the photocatalytic degradation rate of the catalyst to organic pollutants is high, and the method is suitable for industrial production. The stability of a crystal structure and catalytic activity can be kept under long-term illumination, and the functional application of a photocatalytic air purification technology can be realized by integrating with an illumination lamp.

The invention relates to a method for recovering phosphorus and vanadium from a vanadium-containing salt-removed filter cake, and belongs to the technical field of aluminum oxide preparation. The method comprises the following steps: firstly, preparing vanadium-containing salt elimination filter cake slurry, then adding a dephosphorizing agent into the vanadium-containing salt elimination filter cake slurry, and promoting the dephosphorizing agent to generate precipitation reaction with phosphorus in the slurry to form a precipitate containing phosphorus element, so as to obtain a mixed solution containing the precipitate; next, solid-liquid separation is carried out on the mixed solution, precipitates containing phosphorus elements are filtered out, and the remaining vanadium-containing filtrate is further subjected to impurity removal treatment, so that residual carbonate radicals after the dephosphorization reaction and impurity elements such as arsenic and fluorine in the solution are removed, and adverse effects on the subsequent vanadium precipitation reaction are avoided. And after impurity removal is completed, vanadium precipitation reaction is carried out, and a pure vanadium-containing product is obtained. According to the method, by using the specific dephosphorizing agent, phosphorus in the vanadium-containing salt elimination filter cake is effectively recovered, and the tailing discharge amount is reduced. Meanwhile, the method also improves the concentration of vanadium, is beneficial to the recovery of vanadium, and realizes the simultaneous recovery of phosphorus and vanadium in the vanadium-containing salt elimination filter cake.

The invention provides a method for short-process all-component echelon recovery of a waste hydrogenation catalyst, and relates to the field of solid waste treatment. The recovery method of the waste hydrogenation catalyst comprises the following steps: roasting the waste hydrogenation catalyst and sodium carbonate to obtain a roasted product; the roasted product is leached with water, and leaching liquid and leaching residues are obtained; extracting the leaching solution by using an extracting agent to obtain a vanadium-molybdenum-containing organic phase, sequentially carrying out reverse extraction treatment on the vanadium-molybdenum-containing organic phase by using a strong alkaline reverse extraction agent and a weak alkaline reverse extraction agent to obtain a vanadium reverse extraction solution and a molybdenum reverse extraction solution, and carrying out vanadium precipitation treatment on the vanadium reverse extraction solution to obtain ammonium metavanadate; acidizing the molybdenum strip liquor to precipitate molybdenum to obtain ammonium molybdate; carrying out sintering treatment on the leaching residues and alkaline substances, leaching obtained calcine with water to obtain water leaching residues and filtrate, and carrying out aluminum precipitation treatment on the filtrate to obtain aluminum hydroxide, aluminum oxide or pseudo-boehmite; and reducing and smelting the water leaching residues to obtain the ferro-nickel alloy. According to the invention, multi-element comprehensive recovery of all components of vanadium, molybdenum, nickel, aluminum and sulfur can be realized, and high-value utilization of all components of the waste hydrogenation catalyst is realized.

The invention discloses a bismuth vanadate material for carbon dioxide electroreduction and a preparation method and application, and belongs to the technical field of carbon dioxide electroreduction.The method comprises the steps that bismuth salt is dissolved in a nitric acid aqueous solution, a surfactant is added, and a mixed solution A is obtained through a stirring reaction; dissolving ammonium metavanadate in a sodium hydroxide aqueous solution, adding a surfactant, and carrying out a stirring reaction to obtain a mixed solution B; and mixing the mixed solution A and the mixed solution B, adjusting the pH value to be neutral, and carrying out stirring reaction, hydrothermal reaction, washing, drying and calcination reaction to obtain the bismuth vanadate material for carbon dioxide electroreduction. The preparation method comprises the following steps: uniformly mixing bismuth salt and ammonium metavanadate with a surfactant respectively, and roasting through a hydrothermal method and a template effect of the surfactant to prepare the bismuth vanadate material with high specific surface area for electroreduction of carbon dioxide. In carbon dioxide electroreduction, the catalyst has catalytic performance of high activity, good stability and high selectivity and electrochemical performance of low overpotential and high current density.

The present invention provides a general salt-assisted chemical vapor deposition (SA-CVD) synthetic method for the high-yield preparation of 1D hexagonal-phase MxV6S8(M=K, Rb, Cs) and KxV6SySe8-y nanowires. The resulting nanowires exhibit typical metallic properties, which can be used as a good van der Waals contact for achieving high-performance fermi level pinning free transistors. The present synthesis method allows a more systematic investigation of the intrinsic properties of hexagonal-phase V6S8 structures.

The invention discloses a method for synergistically extracting vanadium oxytrichloride, gallium trichloride and iron-titanium alloy from vanadium slag, and belongs to the field of recycling of complex multi-metal resources. The method comprises the following steps: uniformly mixing the gallium-containing vanadium slag, carbon and chlorinated waste salt according to a certain proportion, and carrying out vacuum melting treatment to obtain a Fe-Ti alloy; then chlorine is introduced for chlorination treatment, and a gaseous product is obtained; the gaseous product is adsorbed by a molecular sieve with a function of selectively adsorbing VOCl3 to obtain VOCl3, and then GaCl3 is obtained through a cold trap. According to the method, efficient collaborative conversion and recovery of multi-metal resources of vanadium, gallium, iron and titanium in the vanadium slag are achieved, and the problems that multi-metal collaborative extraction in existing vanadium slag is difficult, and the separation efficiency is low can be effectively solved.

The invention discloses a modified solid-state electrolyte and a preparation method and application thereof, and relates to the field of solid-state batteries, in 300 crystal face grain size distribution of the modified solid-state electrolyte, Kn90 = (Ln90-Ln10) / Ln50, and Kn90 is more than or equal to 0.5 and less than or equal to 1.7; wherein Ln10 is the corresponding grain size when the volume distribution cumulative percentage of the 300 crystal face sub-grain size Ln of the modified solid electrolyte reaches 10%, and Ln50 is the corresponding grain size when the volume distribution cumulative percentage of the 300 crystal face sub-grain size Ln of the modified solid electrolyte reaches 50%; ln90 is the corresponding grain size when the volume distribution cumulative percentage of the 300 crystal face sub-grain size Ln of the modified solid electrolyte reaches 90%. According to the invention, the modified solid electrolyte has excellent ionic conductivity, good air stability, interface stability to metal lithium and relatively high oxidation potential stability.

The invention relates to a novel layered sulfide positive electrode material of a lithium ion battery, which has a general formula of Li (1.33-0.33 x) VxTi (0.67-0.67 x) S2, and x is more than or equal to 0 and less than or equal to 0.5. The positive electrode material belongs to a hexagonal system O3 type crystal structure, the corresponding space group is # imgabs0 #, the microstructure of the positive electrode material is granular, the particle size of the particles is about 20-50 microns, and all elements are uniformly distributed on the surfaces and inside the particles. In the positive electrode material, almost all capacities come from the oxidation-reduction reaction of sulfur, and the capacity contribution of vanadium can be almost ignored. An electrochemical test and a solid-state nuclear magnetic characterization result show that the Li1. 27V0. 2Ti0. 53S2 positive electrode material has the reversible capacity as high as 308mAh g <-1 >, and reversible de-intercalation of all Li < + > in a system is realized. Meanwhile, the material shows extremely excellent rate and cycle performance, still has a capacity retention ratio of 81.0% after 4300 cycles, and almost has no voltage attenuation in the cycle process.

The invention discloses an anode active material and a preparation method thereof, a composite photoelectrode and a super capacitor battery, and relates to the technical field of electrochemical energy storage, the anode active material comprises oxygen-deficient bismuth vanadate and lanthanum chloride loaded on the oxygen-deficient bismuth vanadate, and the anode active material has pores. According to the invention, bismuth vanadate in the anode active material has oxygen defects, so that the conductivity of the bismuth vanadate electrode is improved, and the separation of electrons and holes in a bismuth vanadate bulk phase is promoted; lanthanum chloride in the anode active material promotes the injection efficiency of carriers on the surface of the bismuth vanadate electrode, the valence band structure of bismuth vanadate is changed, and the conductivity is greatly improved; in addition, the anode active material has pores, so that enough mechanical strain space is provided in the charging and discharging process, the volume expansion of bismuth is relieved, and the stability of the electrode is improved.

The present invention provides a preparation method for a 3 / 4-valent vanadium sulfate-hydrochloric acid electrolyte, comprising the following steps: adding hydrochloric acid into a 4-valent vanadium sulfate electrolyte to prepare a 4-valent vanadium sulfate-hydrochloric acid electrolyte; preparing a (4+x)-valent vanadium sulfate electrolyte; using the (4+x)-valent vanadium sulfate electrolyte and the 4-valent vanadium sulfate-hydrochloric acid electrolyte respectively as positive and negative electrode electrolytes of an all-vanadium redox flow battery to perform charging electrolysis, to obtain a (4+y)-valent vanadium sulfate electrolyte and a 3-valent vanadium sulfate-hydrochloric acid electrolyte at positive and negative electrodes, respectively; and adding oxalic acid into the obtained (4+y)-valent vanadium sulfate electrolyte for reduction to re-obtain the (4+x)-valent vanadium sulfate electrolyte, wherein the re-obtained (4+x)-valent vanadium sulfate electrolyte can be further used to prepare the 3-valent vanadium sulfate-hydrochloric acid electrolyte. The preparation method for a 3 / 4-valent vanadium sulfate-hydrochloric acid electrolyte provided by the present invention features high efficiency and low costs, and the obtained 3 / 4-valent vanadium sulfate-hydrochloric acid electrolyte has a high concentration and a wide operating temperature range.

The invention relates to a method for separating iron, vanadium and titanium dioxide in vanadium titano-magnetite or titanium concentrate through a wet method, and belongs to the technical field of chemical engineering. The method comprises the following steps: (a) mixing vanadium titano-magnetite or titanium concentrate with sulfuric acid with the concentration of 22-30wt.% to obtain mixed slurry; (b) treating the mixed slurry at 150-200 DEG C and 2-4 MPa under the condition that the Reynolds number is gt; reacting in a turbulent flow state of 4000, so that non-titanium elements are dissolved to generate sulfate; (c) carrying out solid-liquid separation on the reaction product in the step (b) to obtain a high-grade titanium-rich material and waste liquid; (d) the titanium-rich material reacts with a sodium hydroxide solution, silicon in the titanium-rich material is removed, and a sodium silicate solution is generated; and (e) reacting the silicon-removed titanium-rich material with a hydrochloric acid solution with the mass concentration of less than 15%, cleaning, carrying out solid-liquid separation, and calcining to obtain anatase or rutile titanium dioxide. According to the method, all iron, vanadium and titanium elements in the vanadium-titanium-iron concentrate and the titanium concentrate are recycled.

The invention provides a sodium metavanadate purification process, and belongs to the technical field of high-purity vanadium processing. Comprising the following steps: A, coating a lower filter belt with sodium metavanadate-containing pug subjected to draining treatment through a feeding mechanism; b, after the sludge is dewatered by the first filter pressing station, part of cleaning liquid generated by cleaning an upper filter belt and a lower filter belt is used for humidifying the sludge which is dewatered for the first time at a primary water adding station; c, dewatering is completed at a second filter pressing station, and part of cleaning liquid generated by cleaning the upper filter belt and the lower filter belt is used for conducting water adding treatment on the pug subjected to secondary dewatering at a secondary water adding station; d, carrying out filter pressing dehydration for the last time; e, removing the filter residues which are finally dehydrated and adhered to the upper surface of the upper filter belt and the lower surface of the lower filter belt at a discharging station; and F, the remaining cleaning liquid is filtered through an upper filter belt in front of the feeding station, and ammonium chloride is added for vanadium precipitation treatment. The method has the advantages of simple process, high yield and the like.

This application provides a KVOH nanomaterial, its preparation method, and an aqueous zinc-ion battery to address the technical problem of low performance of vanadium pentoxide cathode materials in the prior art. The KVOH nanomaterial provided in this application is obtained by a solvothermal reaction in an aqueous ethylene glycol solution. The introduction of potassium ions in the reaction expands the ion transport channels between the electrode material layers, improving the cycle performance of the battery. At the same time, the introduction of tetravalent vanadium also increases the specific capacity of the battery, thereby solving the technical problem of low performance of vanadium pentoxide cathode materials in the prior art.

The invention discloses a method for preparing alkali metal vanadate by a mechanochemical reaction method. The method comprises the following steps: mixing a vanadium-containing compound and an alkali metal compound according to the stoichiometric ratio of a target product, adding or not adding a protic solvent, and grinding to induce a mechanochemical reaction among the raw materials, so as to obtain the alkali metal vanadate, wherein the alkali metal vanadate is selected from one of NaVO3, KVO3, RbVO3, CsVO3, Rb3V5O14, Cs2V4O11 and Li3VO4, and the alkali metal vanadate is selected from one of NaVO3, KVO3, RbVO3, CsVO3, Rb3V5O14, Cs2V4O11 and Li3VO4. The preparation method has the advantages of being environmentally friendly, low in energy consumption, high in reaction efficiency and the like, efficient preparation of all series of alkali metal vanadate can be achieved, and the obtained alkali metal vanadate is high in purity, small in particle size and good in dispersity and has potential application value in the fields of lithium ion batteries, photocatalysis, laser crystals and the like.

The invention relates to a vanadyl sulfate electrolyte based on shale vanadium-rich liquid and a preparation method of the vanadyl sulfate electrolyte. According to the technical scheme, the shale vanadium-rich liquid is subjected to reduced pressure evaporation, and high-concentration vanadium-rich liquid is obtained; standing the high-concentration vanadium-rich liquid in a low-temperature environment for cooling crystallization, and carrying out solid-liquid separation for the first time to obtain a high-purity vanadium-rich liquid; according to the solid-to-liquid ratio of 1-15 Kg / t, seed crystals and the high-purity vanadium-rich liquid are mixed and stirred, and turbid liquid is obtained; crystallizing the turbid liquid in a constant-temperature environment; carrying out secondary solid-liquid separation to obtain vanadyl sulfate crystals; and dissolving the vanadyl sulfate crystal in a dilute sulfuric acid solution according to a solid-to-liquid ratio of 400-575 Kg / t to prepare the vanadyl sulfate electrolyte based on the shale vanadium-rich liquid. The method has the characteristics of being simple in process, low in medicament consumption, environment-friendly, high in safety and convenient to adjust the vanadium concentration of the electrolyte, the prepared vanadyl sulfate electrolyte based on the shale vanadium-rich liquid is high in purity, and separation of vanadium and impurities in the shale vanadium-rich liquid is effectively achieved.

The application relates to a novel lithium ion battery layered sulfide positive electrode material, which has a general formula of Li 1.33‑0.33x V x Ti 0.67‑0.67x S2, and 0<=x<=0.5. The positive electrode material belongs to a hexagonal crystal structure of O3 type, and a corresponding space group is P63 / mmc. The micro-morphology of the positive electrode material is granular, the particle size is about 20-50 mu m, and each element is uniformly distributed on the particle surface and inside. In the positive electrode material, almost all the capacity comes from the redox reaction of sulfur, and the capacity contribution of vanadium can be ignored. Electrochemical test and solid-state nuclear magnetic characterization results show that the Li 1.27 V 0.2 Ti 0.53 S2 positive electrode material has a reversible capacity of up to 308 mAh g ‑1 , and realizes reversible deintercalation of all Li + in the system. Meanwhile, the material exhibits extremely excellent rate and cycle performance, has a capacity retention rate of 81.0% after 4300 cycles of long cycle, and has almost no voltage attenuation in the cycle process.

The invention discloses a bismuth-based nanofiber photocatalytic material as well as a preparation method and application thereof, and belongs to the technical field of photocatalytic materials. The material is prepared by taking bismuth as a matrix and introducing vanadium, halogen or molybdenum elements through an electrostatic spinning and staged calcining process. The obtained material is of a three-dimensional nanofiber membrane structure, has a high specific surface area and excellent visible light response characteristics, can synchronously and efficiently photocatalytically degrade organic pollutants in electroplating wastewater and reduce and fix heavy metal ions, is easy to separate and recover, has good cycle stability, and is suitable for industrial production. And an efficient and green technical scheme is provided for deep treatment of the electroplating wastewater.

A solid electrolyte, a method of manufacturing the same, and a lithium battery including the solid electrolyte. The solid electrolyte may include a solid ion conductor represented by Formula 1:LiaBbAlmQnOcXd  Formula 1wherein, in Formula 1, Q is an element that has an ionic radius that differs from an ionic radius of Al by less than 30% and has +3 and +5 valence states, X is at least one of F, Cl, Br, or I, 3.5≤a≤4.5, 3≤b<5.2, 1≤m≤3, 0<n<2, 11≤c≤13, and 0<d≤1.5.

An all-solid-state battery having a positive electrode, a negative electrode having a negative electrode active material layer, and a solid electrolyte layer between the positive electrode and the negative electrode material layer. The negative electrode active material layer contains 60% by volume or more of an oxide having a LISICON-type crystal structure. The solid electrolyte layer contains a solid electrolyte having at least one of an oxide having a garnet-type crystal structure or an oxide having a LISICON-type crystal structure.

The invention belongs to the technical field of electrode materials, and provides a silver-vanadium oxide positive electrode material and a preparation method and application thereof, the chemical formula of the silver-vanadium oxide positive electrode material is Ag2V4O11, and the specific surface area is 0.6-1.5 m < 2 > / g; under the instantaneous current of 20mA / cm < 2 >, the average lag voltage is less than 350mV; under the instantaneous current of 40mA / cm < 2 >, the average lag voltage is less than 580mV; the BET is controlled within the range of 0.6-1.5 m < 2 > / g, so that the silver vanadium oxide positive electrode material capable of sufficiently reducing or avoiding the influence of internal resistance increase and voltage delay can be obtained. According to the design of the preparation method, low-temperature pre-calcination is carried out based on a decomposition window determined by DSC to form a segmented heat treatment process, the crystallinity and integrity of the silver-vanadium oxide crystal are remarkably improved, and the specific surface area (BET) of the material can be synchronously reduced, so that the specific surface area of the material reaches 0.6-1.5 m < 2 > / g.

The invention discloses an L-cysteine doped ammonium vanadate positive electrode material, a preparation method thereof and application of the L-cysteine doped ammonium vanadate positive electrode material in an aqueous zinc ion battery, and belongs to the technical field of materials. The preparation method comprises the following steps: adding ammonium metavanadate and oxalic acid into deionized water, stirring and mixing, then adding L-cysteine, carrying out hydrothermal reaction on the obtained mixed solution, cooling to room temperature, carrying out centrifugal cleaning, and carrying out vacuum drying to obtain the L-NVO. L-NVO is prepared through a simple one-step hydrothermal method, L-cysteine is doped into the electrode material through further reaction, the introduction of L-cysteine not only enlarges the interlayer spacing of NVO, but also participates in the storage of zinc ions, increases the active sites of the zinc ions, effectively promotes the diffusion of ions and charge transfer, and improves the electrochemical performance of the electrode material. The conductivity of the material is improved, the internal resistance of the material is reduced, and the structural flexibility and stability of the material are maintained, so that the overall performance of the aqueous zinc ion battery is improved.

The invention belongs to the technical field of vanadium extraction, and particularly discloses large-size high-density ammonium metavanadate and a preparation method thereof. The method comprises the following steps: (1) roasting and crushing the vanadium slag to obtain refined vanadium slag; (2) carrying out alkaline leaching, acid adjustment and impurity removal on the refined vanadium slag to obtain a vanadium precipitation stock solution; (3) polyvinylpyrrolidone and soluble ammonium salt are added into the vanadium precipitation stock solution, the number-average molecular weight of the polyvinylpyrrolidone is 7000-10000, and the polyvinylpyrrolidone and the soluble ammonium salt react for 40-80 min at the temperature of 30-50 DEG C; and (4) after the reaction is finished, carrying out solid-liquid separation to obtain the large-size high-density ammonium metavanadate. In the vanadium precipitation process, polyvinylpyrrolidone is added as a surface dispersant and a nucleation modifier, so that the apparent density of an ammonium metavanadate product can be improved, the particle size of ammonium metavanadate is increased, and industrial application of ammonium metavanadate is facilitated.

The invention discloses a vanadium-based sulfide heterostructure preparation method, which comprises: 1) respectively grinding a copper source, a vanadium source and a sulfur source through a mortar, adding into deionized water, uniformly stirring at a room temperature, and adjusting the pH value of the system to 10-13 to obtain a mixed solution; 2) transferring the mixed solution into deionized water, uniformly mixing, and carrying out heating reaction; and after the reaction is finished, cooling, centrifuging and drying to obtain the vanadium-based sulfide heterostructure. CuS is introduced into Cu3VS4 by a hydrothermal method to construct a heterostructure, the electron mobility of the material is improved, the conductivity and magnesium ion diffusion power are further improved, the specific capacity of the prepared Cu3VS4 / CuS is excellent, and the capacity can reach 200 mAh / g after activation; the preparation method is simple and convenient in process, wide in applicability, high in safety performance, capable of accurately regulating and controlling the phase content, low in reaction raw material and equipment requirements and capable of being popularized and applied on a large scale.

The invention belongs to the field of magnesium ion battery positive electrode materials, and particularly relates to a preparation method of a magnesium ion battery positive electrode material BixVS4 composite material, which comprises the following steps: dissolving an organic reducing agent in N-methyl pyrrolidone, and stirring at room temperature; adding ammonium metavanadate, and stirring at 50-100 DEG C; adding thioacetamide, and continuously stirring; adding hydrochloric acid and stirring until the color of the solution becomes dark green; and adding bismuth nitrate pentahydrate, stirring, carrying out a hydrothermal reaction in a reaction kettle, cooling to room temperature, centrifuging, washing with deionized water and absolute ethyl alcohol for several times, and drying to obtain the BixVS4 composite material. The method has the advantages that VS4 is subjected to cation modification, high conductivity is provided by introduction of metal ions, and charge transfer is accelerated. Bi enters a VS4 crystal lattice, local charge rearrangement is caused, Van der Waals force between VS4 layers is weakened, rapid embedding and de-embedding of Mg < 2 + > are facilitated, and more active sites for embedding of Mg < 2 + > are provided.

The invention relates to the field of vanadium batteries, and discloses a method for preparing a vanadium battery electrolyte from an alkaline vanadium liquid in a short process, which comprises the following steps: adding an adsorbent into the alkaline vanadium liquid to remove impurities to obtain an impurity-removed vanadium liquid; wherein the adsorbent comprises sulfhydrylated chitosan microspheres; the impurity-removed vanadium liquid and a transforming agent are mixed and react, V (OH) 4 + in the impurity-removed vanadium liquid is transformed into VO < 2 + >, and transformed vanadium liquid is obtained; wherein the transforming agent comprises ascorbic acid and sulfite; and the converted vanadium liquid is adjusted to be acidic, a stabilizer is added to obtain a to-be-electrolyzed solution, the to-be-electrolyzed solution is electrolyzed, and an electrolyte containing V < 3 + > and VO < 2 + > is obtained. The preparation process of the electrolyte can be effectively shortened, impurity interference is avoided, and the current efficiency is improved.

In order to efficiently reduce the concentration of contaminants in an electrolyte liquid suitable for a redox flow battery, the electrolyte liquid (101), after passing through the negative half cells of the single cell stack (4) or of the several cell stacks, passes through positive half cells of the single cell stack or of the several cell stacks of the redox flow battery purifier (1), without passing through a second tank, via a connecting device (10) that interconnects the negative half cells and the positive half cells of a cell stack.

The invention belongs to the technical field of wet vanadium extraction, and particularly relates to large-granularity ammonium metavanadate and a preparation method thereof. Comprising the following steps: (1) preparing a vanadium-containing stock solution; (2) dissolving ammonium salt and high-molecular-weight polyethylene glycol in water, and adding alkali to adjust the pH value to obtain an ammonium salt solution; (3) adding low molecular weight polyethylene glycol into the vanadium-containing stock solution to obtain a modified vanadium-containing stock solution; (4) uniformly mixing an ammonium salt solution and the modified vanadium-containing stock solution, adjusting the pH value, and reacting to obtain a mixture; and (5) filtering the mixture, and washing a solid product to obtain large-granularity ammonium metavanadate. The low molecular weight polyethylene glycol mainly plays a role in reducing the nucleation rate; the high-molecular-weight polyethylene glycol is good in adsorbability and mainly plays a role in promoting crystal growth, and the particle size of ammonium metavanadate is increased through mutual cooperation of the polyethylene glycol with different molecular weights. The method is simple in process, environment-friendly, free of wastewater and waste residue discharge and beneficial to industrial popularization and application.

The invention relates to the related technical field of magnesium ion batteries, and particularly discloses a magnesium vanadium oxide positive electrode material with a spinel structure and a preparation method of the magnesium vanadium oxide positive electrode material. The preparation method comprises the following steps: step 1, mixing vanadium pentoxide and magnesium oxide according to a molar ratio of vanadium pentoxide to magnesium oxide of 1: (3-3.2), and grinding to obtain mixed powder; 2, the mixed powder is heated to 900 DEG C to 1200 DEG C, heat preservation is conducted for 2 h to 24 h, and magnesium orthovanadate is obtained; and 3, heating magnesium orthovanadate in a reducing atmosphere of a mixed gas composed of hydrogen and argon for 4-16 h at 450-900 DEG C to obtain the positive electrode material. The positive electrode material prepared by the preparation method disclosed by the invention has a spinel structure, and the problem of dynamic retardation of a water-based magnesium ion battery is solved.

The present invention relates to an oxygen ion conductor material with high oxygen ion conductivity in the medium and low temperature range and a preparation method thereof. The chemical composition of the material is represented by: Bi4(V 1‑y M y ) x O 11+z , wherein M is a metal cation, 1.7≤x≤2.2 and x≠2, 0<y≤0.3, and z depends on the neutral balance of the metal cation composition. The modified bismuth vanadate Bi4 (V 1‑y M y ) x O 11+z Materials have simple preparation process, low cost, stable structure and high conductivity, among which Bi4(V 0.9 Cu 0.1 ) 1.9 O 10.465 At 300℃, the grain conductivity is 10 ‑2 S / cm level, the total ionic conductivity of ceramics reaches 1.2×10 ‑3 S / cm, which is about 1 order of magnitude higher than the current highest value reported in the literature, and can meet the application requirements of medium and low temperature oxide fuel cells and oxygen sensors.