49 results about "Sodium ferrocyanide" patented technology

This invention belongs to the field of sodium-ion battery material preparation technology, specifically relating to sodium-ion battery cathode sodium supplementation additives, their preparation methods, and applications. The sodium-ion battery cathode sodium supplementation additive of this invention uses sodium ferrocyanide as the main component, and has a specific surface area greater than 1000 m². 2 The first conductive carbon (g) is impregnated and adsorbed, and then ball-milled and mixed with a second conductive carbon with better conductivity to obtain a sodium-ion battery cathode additive. When the cathode of the battery uses the sodium-ion battery additive of this invention, the dissolved metal ions M react with sodium ferrocyanide Na4[Fe(CN)6] adhering to the cathode material to form Prussian blue Na2M[Fe(CN)6] small crystals, which can continuously exert sodium storage performance for a period of time, delaying the capacity and lifespan decay of the battery; and Na is released during the formation of small crystals Na2M[Fe(CN)6]. + It plays a role in continuously replenishing sodium during the use of sodium-ion batteries, further delaying capacity decay.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a Prussian blue sodium battery positive electrode material and a preparation method thereof.The preparation method comprises the steps that anhydrous sodium ferrocyanide, anhydrous manganese sulfate and a NaA molecular sieve are mixed and preliminarily ground, and a precursor mixture is obtained; placing the precursor mixture in a planetary ball mill for ball milling to obtain a primary reaction product; and washing the preliminary reaction product, and carrying out vacuum drying to obtain the Prussian blue sodium battery positive electrode material. The method is low in material loss and short in generation period, and the prepared Prussian blue sodium battery positive electrode material is low in crystal water content and has good cycle stability.

The invention discloses a lanthanide-doped Prussian blue positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing and dissolving sodium ferrocyanide and lanthanide metal salt to obtain a mixed solution; and under a protective atmosphere, dropwise adding the mixed solution into a mixed chelating agent salt solution through a peristaltic pump, and reacting to obtain the lanthanide-doped Prussian blue positive electrode material. The lanthanide metal in the lanthanide-doped Prussian blue positive electrode material occupies the Na site, the single iron source coprecipitation method is adopted for synthesis, the process concentration is uniform, the synthesized positive electrode material has fewer defects, the material structure is stable, the rate capability is excellent, the specific capacity is high, and the application prospect is very good.

The invention relates to a production process of a purple pigment with high color fidelity and dyeing uniformity. Comprising the following steps: 1) adding a copper sulfate solution into a dissolving solution containing basic purple 5BN and basic fuchsin, uniformly stirring, and heating to 78-85 DEG C to obtain a material A; (2) adding the sodium ferrocyanide solution into the material A in 70-90 minutes, maintaining the temperature, and uniformly stirring to obtain a material B; 3) adding the sodium sulfite solution into the material B, continuously stirring uniformly, adding the sodium ferrocyanide solution again, and stirring uniformly to obtain a material C; the preparation method comprises the following steps of 1, adding a material C into a reaction kettle, 2, adding ammonia water into the material C, adjusting the pH value to 7.5-8, and stirring for 25-35 min to obtain a material D, 5, maintaining the temperature of the material D, and carrying out emulsification dispersion treatment to obtain a material E, and 6, cooling the material E to a temperature below 60 DEG C to obtain a material F, and carrying out post-treatment on the material F to obtain the pink purple pigment. The pigment obtained through the above scheme has high purple color fidelity and dyeing uniformity.

The application discloses a nickel-based Prussian blue battery positive electrode material and a preparation method and battery thereof, and belongs to the technical field of batteries, wherein the preparation method of the nickel-based Prussian blue battery positive electrode material comprises the following steps: dissolving sodium citrate into a nickel chloride solution to obtain reagent A; dissolving sodium ferrocyanide in water to prepare a solution to obtain reagent B; dissolving polyvinylpyrrolidone in a sodium chloride solution to obtain reagent C; simultaneously and slowly adding the reagent A and the reagent B into the reagent C to obtain a suspension liquid and aging the suspension liquid; centrifugally separating the suspension liquid after aging, washing, drying and grinding to obtain the nickel-based Prussian blue battery positive electrode material; and the nickel-based Prussian blue battery positive electrode material prepared by the application has the characteristics of high capacity, low alternating current impedance and high long cycle stability, and has excellent electrochemical performance.

The invention belongs to the technical field of energy materials, and particularly relates to preparation and application of a high-crystallinity long-life Prussian blue and analogue positive electrode material thereof. Aiming at the defects in the prior art, the invention provides the preparation method of the high-crystallinity long-life Prussian blue and the analogue thereof, which comprises the following steps: 1) mixing soluble transition metal M salt and a solvent to obtain a solution A; 2) mixing sodium ferrocyanide salt, sodium salt and a solvent to obtain a solution B; adding a complexing agent or / and an acid for regulating and controlling the chelating ability into the solution A, adding a complexing agent or / and an acid for regulating and controlling the chelating ability into the solution B, and controlling the total molar ratio of the complexing agent to the acid for regulating and controlling the chelating ability in the solution A and the solution B to be (20-1): 1; and 3) dropwise adding the solution A into the solution B, reacting, aging, centrifuging, washing and drying to obtain the Prussian blue and the analogue thereof. The method disclosed by the invention greatly widens the selection range of the chelating agent in the production process of the Prussian blue analogue positive electrode.

The application discloses a kind of low-defect manganese-based prussian blue under solid-liquid dynamic balance fast preparation method, comprising the following steps: S1, sodium citrate is dissolved in deionized water, then add manganese acetate and ascorbic acid, form the solution A containing manganese complex;Wherein, the molar ratio of sodium citrate, manganese acetate and ascorbic acid is (4.5-5.5): 1:(0.3-0.4);S2, sodium ferrocyanide is added to deionized water, stirring is formed at a set temperature containing unsolved sodium ferrocyanide solid supersaturated suspension B;Wherein, the addition amount of sodium ferrocyanide is far more than its saturated solubility at the temperature, so that the system maintains solid-liquid two-phase equilibrium state;Crystalline integrity is higher: thanks to "whole process dynamic saturation" environment, the manganese-based prussian blue prepared by the application has more obvious monoclinic phase characteristics (corresponding XRD double peak is obvious, intensity is obvious, signal-to-noise ratio is good) compared with comparative document, lattice vacancy and coordination water content are significantly lower than comparative document scheme, and electronic conductivity is increased by nearly 50%.

The application relates to the technical field of sodium ion battery electrode materials, in particular to a polyaniline-coated Prussian blue analogue positive electrode material for a sodium ion battery and a preparation method thereof. The material is synthesized by using a room-temperature co-precipitation method combined with an in-situ oxidation polymerization method, and comprises the following steps: step one, dissolving ferrous sulfate heptahydrate and sodium citrate in deionized water to obtain solution 1; step two, dissolving sodium ferrocyanide decahydrate in deionized water to obtain solution 2. The PBA@PANI composite material is used as a positive electrode of a sodium ion battery, and in the cycle test, the PBA@PANI composite material exhibits a significantly improved capacity retention rate, excellent rate performance and a stable working voltage platform. Meanwhile, the polyaniline-coated Prussian blue analogue composite material prepared by the process has high specific capacity and long cycle life, and provides an efficient solution for the practical application of a high-performance and low-cost sodium ion battery positive electrode material.

The invention discloses a vacancy content controllable Prussian blue crystal as well as a preparation method and application thereof, and belongs to the technical field of material synthesis. In order to solve the technical problems that the vacancy content of a prussian blue material is difficult to accurately control and a vacancy-free material is difficult to prepare, the invention provides a series of prussian blue crystals with controllable vacancy content, and the preparation method comprises the following steps: mixing sodium ferrocyanide, a complexing agent, a sodium salt and water to obtain a solution A; mixing soluble manganese salt, soluble ferrous salt, a complexing agent, sodium salt and water to obtain a solution B; and controlling the sodium ion concentration and the reaction atmosphere and temperature, adding the solution A into the solution B, reacting, and aging to obtain the Prussian blue crystal. According to the method, the sodium ion concentration, the reaction atmosphere and the temperature are regulated and controlled by changing the addition amount of the sodium salt and the like, and the crystal growth speed and the ion transmission speed in the coprecipitation reaction are controlled, so that the purpose of accurately controlling the vacancy content is achieved, and a material without vacancy and first-stage crystal water can be prepared.

The application provides a single crystal type high-entropy Prussian blue positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing a transition metal salt solution, a sodium ferrocyanide solution, a complexing agent solution, a base solution and a precipitant, performing a co-precipitation reaction under the condition that the pH value is 10-13, then performing standing and aging, and sequentially performing filtration, washing and drying to obtain the single crystal type high-entropy Prussian blue positive electrode material. The single crystal type high-entropy Prussian blue positive electrode material obtained by the application has a high material thermal decomposition temperature and excellent thermal stability; vacancies in the positive electrode material and a small amount of water content can inhibit the dissolution of metals; in addition, the single crystal type high-entropy Prussian blue positive electrode material obtained by the application has excellent morphology.

The application provides a preparation method of a sodium-rich and low-water-content Prussian blue positive electrode material, which comprises the following steps: dissolving sodium ferrocyanide or a hydrate thereof and a complexing agent in deoxygenated water under an inert gas atmosphere and at a certain temperature to obtain a mixed solution A; dissolving a transition metal salt or a hydrate thereof, a sodium supplementing agent, a complexing agent and an auxiliary complexing agent in deoxygenated water under an inert gas atmosphere and at a certain temperature to obtain a mixed solution B; continuously stirring solution A and solution B by dropwise adding them into a container with a positive pressure inert gas atmosphere and at a certain temperature, continuing to stir for a period of time after the dropwise adding is completed, and then standing, centrifuging and vacuum drying to obtain the Prussian blue positive electrode material. The Prussian blue positive electrode material comprises a mixed phase structure of rhombic phases and cubic phases, has the characteristics of high sodium content and low water content. The battery assembled by using the positive electrode material obtained by the method has a theoretical specific capacity close to the theoretical specific capacity under a small current density and still has a high specific capacity under a large current density.

The present invention relates to a process for producing a composite ferrocyanide adsorbent of a transition metal in the silica gel matrix comprising the following steps: (i) the preparation of a first aqueous composition comprising at least a mixture of a sodium or potassium ferrocyanide with a sodium silicate solution so as to obtain the dissolution of salts; (ii) the preparation of a second composition comprising a mixture of at least: a transition metal salt selected from one or more of the following compounds: nickel, copper, zinc, cobalt, and an inorganic acid; (iii) the mixing of the first aqueous composition with the second composition until a suspension is obtained; (iv) the addition of an inorganic acid or base so that the suspension obtained at the end of step (iii) has a pH ranging from 4 to 9;(v) the separation of the suspension obtained at the end of step (iv) so as to obtain a precipitate within a liquid phase; (vi) the separation of said precipitate, the rinsing and drying of the precipitate, so as to obtain a solid precipitate, characterized in that the first aqueous composition comprises a soluble salt of rubidium or cesium, and the second composition further comprises a soluble salt of metal selected from one or more of the following compounds: aluminium, titanium, zirconium.;

A method for preparing a Prussian blue-based sodium-ion battery cathode material with both high capacity and long cycle performance, belonging to the field of sodium-ion batteries, includes the following steps: Step 1, preparing a sodium ferrocyanide solution, denoted as solution A; Step 2, dissolving a transition metal divalent ferric salt, a doped metal salt, ascorbic acid, and a complexing agent in deionized water, denoted as solution B; Step 3, preparing an aqueous solution of the complexing agent, denoted as solution C; Step 4, simultaneously adding solutions A and B in equal molar amounts to solution C for a co-precipitation reaction, aging the solution to obtain a suspension, separating the suspension to obtain the Prussian blue-based sodium-ion battery cathode material with both high capacity and long cycle performance. This invention proposes a synthesis method that only requires co-precipitation through a combination of slow crystallization and ion doping to obtain a low-cost, non-toxic, harmless, simple preparation process, short production cycle, and Prussian blue-based sodium-ion cathode material with both high capacity and long cycle performance.

The invention discloses a rapid preparation method of low-defect manganese-based Prussian blue under solid-liquid dynamic equilibrium, which comprises the following steps: S1, dissolving sodium citrate in deionized water, and then adding manganese acetate and ascorbic acid to form a solution A containing a manganese complex; wherein the molar ratio of the sodium citrate to the manganese acetate to the ascorbic acid is (4.5-5.5): 1: (0.3-0.4); s2, adding sodium ferrocyanide into deionized water, and stirring at a set temperature to form a supersaturated turbid liquid B containing an undissolved sodium ferrocyanide solid; wherein the addition amount of the sodium ferrocyanide far exceeds the saturation solubility of the sodium ferrocyanide at the temperature, so that the system is kept in a solid-liquid two-phase equilibrium state; benefited from the whole-process dynamic saturation environment, compared with a comparison file, the manganese-based Prussian blue prepared by the method has more obvious monoclinic phase characteristics (corresponding to obvious XRD double peaks, obvious strength and good signal-to-noise ratio), the lattice vacancy and coordinated water content are obviously lower than those of a comparison file scheme, and the electronic conductivity is increased by nearly 50%.

The invention discloses an anode catalyst as well as a rapid Joule heat preparation method and application thereof. Mixing the nickel ion solution with the iron ion solution to obtain a mixed metal ion solution; dropwise adding the mixed metal ion solution into a sodium ferrocyanide solution, mixing and dispersing, and carrying out centrifugal separation and drying to obtain a precursor material; the foamed nickel is sequentially subjected to ethanol ultrasonic treatment and then immersed in nitric acid for ultrasonic cleaning; and mixing the pretreated foamed nickel with the precursor material obtained in the step 1, carrying out rapid Joule heat treatment under the protection of inert gas, and cooling to obtain the anode catalyst. The anode catalyst material prepared through rapid Joule heat treatment shows excellent electrochemical (OER) oxygen evolution reaction catalytic performance, the overpotential reaches 220 mV under the current density of 10 mA cm <-2 >, and compared with a commercial anode catalyst material prepared through a traditional method, the overpotential is reduced by about 30-100 mV.

The invention discloses a low-potential Prussian blue positive electrode material as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing a precipitant solution and a metal salt solution to carry out coprecipitation reaction, filtering and washing to obtain a washed filter cake; and adding the washed filter cake into a treatment solution containing sodium ferrocyanide for pulping, carrying out high-temperature aging treatment under a stirring condition, and then carrying out filtering, washing and drying treatment to prepare the low-potential Prussian blue positive electrode material. In the washing process of a conventional coprecipitation method, the steps of pulping and high-temperature aging in a solution environment containing sodium ferrocyanide are introduced, and ferrocyanide vacancies in a lattice structure are reduced through curing and ion exchange; meanwhile, the method disclosed by the invention is based on an existing technological process, no additional working procedure is added, a solution environment containing sodium ferrocyanide is introduced into an inherent pulping flow of a washing working procedure, and only one-time drying is needed in the whole process.

The invention belongs to the technical field of sodium ion battery electrode materials, and particularly provides a preparation method for synthesizing a Prussian blue analogue sodium ion battery positive electrode material under the assistance of reduced iron powder. The process comprises the following core steps: respectively dissolving sodium ferrocyanide, an iron source compound, reduced iron powder and a complexing stabilizer in deionized water to prepare a precursor solution system; the target product is obtained through the procedures of aging treatment, solid-liquid separation, vacuum drying and the like after multiphase coprecipitation reaction. The material can be used as a high-performance positive electrode active material to be applied to a sodium ion secondary battery system. According to the scheme, a coordination regulation strategy is combined with a coprecipitation technology, precise construction of a material structure is realized by utilizing a regulation function (providing a reduction environment and regulating the valence state of iron in a reaction system) of reduced iron powder, the structural stability of the Prussian blue analogue compound in a long-cycle process is remarkably improved, defects are reduced, and the crystallinity is improved.

The present invention relates to a method for manufacturing a Prussian blue cathode material for sodium batteries using a Taylor reactor. More specifically, the method includes a first mixture preparation step of preparing a first mixture containing an aqueous iron chloride solution, a second mixture preparation step of preparing a second mixture containing an aqueous sodium ferrocyanide solution, a synthesis step of introducing the mixtures prepared in the first mixture preparation step and the second mixture preparation step into a Taylor reactor and reacting them under nitrogen injection conditions to synthesize a Prussian blue analog, a aging step of aging the Prussian blue analog prepared in the synthesis step, a washing and filtration step of washing and filtration the aged Prussian blue analog with a detergent, and a drying step of drying the washed and filtrated Prussian blue analog. The method for manufacturing a Prussian blue cathode material for sodium batteries using the above steps provides a Prussian blue cathode material that exhibits excellent production efficiency and provides sodium batteries with improved charge / discharge efficiency and capacity retention.

The invention discloses a preparation method for sodium sulfate assisted synthesis of a manganese-based Prussian blue positive electrode material, the structural general formula of the prepared manganese-based Prussian blue is NaxMn [Fe (CN) 6] y.ZH2O, x is more than 1 and less than or equal to 2, and y is more than 0.8 and less than 1. The preparation method comprises the following steps: 1, adding sodium ferrocyanide, sodium sulfate and sodium citrate into deionized water, and stirring a solution on a magnetic stirrer to obtain a solution A; according to the method, the manganese-based Prussian blue analogue positive electrode material is prepared by adopting a synergistic coprecipitation process, dynamic balance of nucleation and growth kinetics is realized by accurately regulating and controlling the stoichiometric ratio of the precursor, and the formation of a crystal vacancy defect is effectively inhibited. Experiments show that the process effectively reduces the content of coordinated water and interstitial water in the material, and greatly reduces the probability of occurrence of side reactions. The material based on defect engineering strategy optimization shows excellent lattice structure stability.

This invention relates to the field of solid-state sodium-ion battery technology, and in particular to the preparation of a Prussian blue cathode material and its application in solid-state sodium-ion batteries. First, chelating agent A and chelating agent B are dissolved in beakers A and B, respectively, each containing 50 mL of deionized water. Then, ferrous sulfite heptahydrate (FeSO4·7H2O) and sodium ferrocyanide (Na4Fe(CN)6·10H2O) are weighed and added to beakers A and B, dissolved, and stirred until homogeneous, yielding mixed solutions A and B. Solution A is slowly added dropwise to solution B, stirred, and centrifuged. The mixture is then washed multiple times with deionized water and ethanol to obtain the Prussian blue cathode material. The chelating group of the chelating agent is (CN). ‑ with Fe 2+ The presence of a competitive relationship between SSC and Fe slows down the nucleation and precipitation process, thus increasing the crystallinity of Prussian blue; 2+ The binding energy is weaker than that of Na2EDTA, CMC, and sodium phytate. The addition of chelating agent B effectively alleviates the SSC-assisted synthesis of Prussian blue [Fe(CN)6]. 4‑ The problem of vacancies; the high crystallinity of Prussian blue has structural defects and low water content, resulting in good cycle performance and stability of the battery.

This invention discloses a low-vacancy manganese iron Prussian blue analog cathode material, its preparation method, and its application in sodium-ion battery manufacturing, belonging to the field of sodium-ion battery technology. The method includes: adding sodium ferrocyanide and sodium citrate to deionized water to obtain solution A; adding manganese chloride and sodium citrate to deionized water to obtain solution B; adding solutions A and B to a sodium citrate solution, treating and repeatedly washing the precipitate, and drying to obtain a monoclinic manganese iron Prussian blue analog; adding this to a sodium ethylenediaminetetraacetate solution, and treating to obtain the low-vacancy manganese iron Prussian blue analog cathode material. This invention uses sodium ethylenediaminetetraacetate solution to modify PBAs, which, compared to acid-base etching modification used for Prussian blue analogs, does not produce highly toxic CN. ‑ It also does not produce insoluble hydroxide precipitates, while increasing the sodium content of PBAs, enhancing structural stability, and suppressing the content of lattice water.

The application discloses a Prussian blue compound and a preparation method and application thereof, and the preparation method is as follows: (1) uniformly dispersing a carbon source / nitrogen source, an iron salt and a nickel salt in ethanol, drying, and calcining under an inert atmosphere to obtain FeNi@NCT; (2) dispersing the FeNi@NCT in a sodium ferrocyanide aqueous solution, adjusting pH, standing, washing with deionized water, and drying to obtain a Prussian blue compound, and the Prussian blue compound is also called FeNiPBA / NCT. The preparation method is simple, efficient, green, has strong component adjustability, strong process scalability and is easy to enlarge. The Prussian blue compound prepared by the application has high crystallinity and high conductivity, as a positive electrode material, significantly improves the rate performance and cycle life of a sodium ion battery, and the electrochemical performance far exceeds that of a conventional modified strategy for preparing a Prussian blue positive electrode material, and overcomes the technical defects of the Prussian blue positive electrode material in the sodium ion battery.

The application discloses a carbon-coating process method in a positive electrode material synthesis process of a Prussian blue analogue, and belongs to the technical field of sodium ion battery positive electrode materials. The process respectively prepares a ferrous salt mixed solution containing dispersed conductive materials, a sodium ferrocyanide solution and a sodium salt base solution, and the first two are slowly added to the base solution under an inert atmosphere for a coprecipitation reaction, in-situ carbon-coating between layers is realized with grain growth, and the reaction solution is subjected to standing, cleaning, positive pressure filtration and vacuum drying, and then conductive materials are added and ball milled to complete secondary surface coating. The application realizes internal conductive bridging of the grains and efficient conduction between the particles through twice carbon-coating, simultaneously inhibits particle agglomeration, guarantees uniform grain structure, and the prepared material has excellent high-rate charge-discharge performance while retaining capacity, and the process has strong controllability and is suitable for industrial production.

The application discloses a Prussian blue type positive material and a preparation method and application thereof. The preparation method mainly comprises the following steps: sequentially adding a manganese source, a nickel source, an iron source and a reducing agent into a sodium ferrocyanide solution, and heating to obtain the Prussian blue type positive material; wherein the sodium ferrocyanide solution comprises Na4Fe[CN]6 slow-release tablets and / or Na4Fe[CN]6 capsules. Through tabletting or surface coating of the raw material Na4Fe[CN]6 capsules, and by utilizing the difference in solubility product between manganese, nickel, iron and ferrocyanide, the adding sequence of the reaction raw materials is adjusted, the production efficiency of the Prussian blue type positive material is improved, and the prepared Prussian blue type positive material has excellent electrochemical performance.

The application belongs to the field of production and preparation of sodium-ion battery positive electrode materials, and particularly relates to a hot repair modification method of Prussian white type sodium-ion battery positive electrode material, which comprises the following steps: taking sodium ferrocyanide as a repair agent, and adopting a hot repair method to obtain a Prussian white analog without defects and low crystallization water. The obtained manganese-based Prussian white analog presents a monoclinic structure, and has an elliptical flake shape with a particle size of 100-300 nm. The application removes crystallization water, repairs defects and supplements sodium through a low-temperature hot repair technology, so that a sodium-rich monoclinic structure crystal (LQMnHCF-R) with complete skeleton is obtained from a low-quality cubic manganese-based Prussian white analog (LQMnHCF), and the crystal exhibits good electrochemical sodium storage behavior. The application has a short process flow, low cost, and a repair agent which can be recycled and is suitable for large-scale production.

The invention belongs to the technical field of sodium-ion battery electrode materials, and particularly provides a sodium-ion battery manganese-based Prussian blue analogue based on manganese acetate and a preparation method of the sodium-ion battery manganese-based Prussian blue analogue. The process comprises the following core steps: respectively dissolving sodium ferrocyanide, a manganese source compound, a sodium supplementing agent and a complexing stabilizer in deionized water to prepare a precursor solution system; the target product is obtained through the procedures of aging treatment, solid-liquid separation, vacuum drying and the like after multiphase coprecipitation reaction. The material can be used as a high-performance positive electrode active material to be applied to a sodium ion secondary battery system. According to the scheme, a coordination regulation strategy is combined with a coprecipitation technology, manganese acetate is used as a manganese source, the manganese-based Prussian blue analogue is synthesized, the water content of crystal lattices is reduced, the electrochemical stability is improved, and the structural stability of the manganese-based Prussian blue analogue in the circulation process is effectively improved.

The invention relates to a preparation method of a transition metal ion doped and regulated Prussian blue sodium-ion battery positive electrode material, and belongs to the technical field of sodium-ion battery positive electrode materials. The preparation method comprises the following steps: completely dissolving sodium ferrocyanide, a complexing agent and sodium salt in deionized water to obtain a solution A; completely dissolving ferric salt, transition metal salt, a complexing agent and sodium salt in deionized water to obtain a solution B; dropwise adding the solution B into the solution A, carrying out coprecipitation reaction at the temperature of 20-60 DEG C under a stirring condition, standing and aging at room temperature for 12-48 hours, carrying out solid-liquid separation, washing a solid with deionized water and absolute ethyl alcohol in sequence, and drying to obtain a precursor; and carrying out heat treatment on the precursor in a protective atmosphere to obtain the transition metal ion doped and regulated Prussian blue sodium battery positive electrode material. According to the method, toxic gas is not generated, the synthesis temperature is low, the sodium content of Prussian blue is increased, the structural stability is enhanced, and the lattice water content is inhibited.

The invention relates to the field of sodium ion batteries, in particular to a preparation method of a high-stability manganese-based Prussian blue sodium ion battery positive electrode material, the structural general formula of the prepared manganese-based Prussian blue is NaxMn [Fe (CN) 6] y.ZH2O, x is more than 1 and less than or equal to 2, and y is more than 0.8 and less than 1. The preparation method is completed according to the following operation steps: respectively mixing sodium ferrocyanide, divalent manganese salt, a sodium supplementing agent and a chelating agent with deionized water to respectively obtain precursor solutions; the positive electrode material is prepared through a co-precipitation reaction, aging, centrifuging and drying. The material is applied to a sodium-ion battery system and is used as a positive electrode material. Starting from the crystal structure control direction, the high-stability manganese-based Prussian blue sodium ion battery positive electrode material is obtained through a chelating agent-assisted coprecipitation method and the addition of a sodium supplementing agent to slow down the reaction speed, and the high-stability manganese-based Prussian blue sodium ion battery positive electrode material has excellent cycling stability.

This application provides a composite sodium ion cathode material, its preparation method, and its application. The preparation method includes the following steps: (1) preparing sodium ferrocyanide solution A, preparing iron source, antioxidant, and complexing agent into solution B, preparing vanadium source, phosphorus source, and reducing agent into solution C, and preparing sodium source and fluorine source into solution D; (2) adding solution A and solution B in parallel into a container to obtain a first solution, adding solution C and solution D in parallel into a container, adding sodium carbonate solution to adjust the pH to obtain a second solution, and adding the first solution and the second solution in parallel into a reaction vessel to react and obtain Prussian blue / vanadium fluorophosphate material; (3) calcining the Prussian blue / vanadium fluorophosphate material to obtain the composite sodium ion cathode material. In this application, the composite Prussian blue and vanadium fluorophosphate materials are subjected to low-temperature calcination treatment, which can not only improve the stability of the material but also improve its conductivity.

The invention discloses a Prussian blue crystal with precisely controllable grain size as well as a preparation method and application thereof, and belongs to the technical field of material synthesis. In order to solve the technical problem that the grain size of a Prussian blue material is difficult to accurately control, the invention provides the preparation method of the Prussian blue crystal with the accurately controllable grain size, and the preparation method comprises the following steps: mixing sodium ferrocyanide, a complexing agent, sodium salt and water to obtain a solution A; mixing soluble manganese salt, soluble ferrous salt, a complexing agent, sodium salt and water to obtain a solution B; and adding the solution A into the solution B in an inert atmosphere, reacting, and aging to obtain the Prussian blue crystal. According to the method, soluble manganese salt, soluble ferrous salt and sodium ferrocyanide are adopted as raw materials, and the crystal nucleation and growth time is controlled by controlling the concentration ratio of a complexing agent to transition metal ions in a solution B, so that the grain size of the Prussian blue crystal is precisely controllable within 20 nm to 30 microns.