173 results about "Cobalt carbonyl" patented technology

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to cobalt carbonate and a preparation method thereof, cobaltosic oxide and a lithium ion battery. The crystal grain size of the cobalt carbonate (104) crystal face is 200-250, and the median particle size Dv50 is 16-20 [mu] m. The preparation method of the cobalt carbonate comprises the following steps: adding a precipitant solution and a cobalt salt solution into a reaction kettle in a parallel flow manner, carrying out a co-precipitation reaction, controlling the reaction pH value, starting a thickener when the volume of a material in the reaction kettle reaches a target value, continuing the reaction until large-particle cobalt carbonate slurry is obtained, and carrying out solid-liquid separation and washing to obtain the cobalt carbonate. Cobalt carbonate is subjected to first sintering, mixed with a doping agent and then subjected to second sintering, and cobaltosic oxide with the (311) crystal face grain size being 660-700 and the median particle size Dv50 being 14-18 microns is prepared. The cobaltosic oxide is high in mechanical strength and good in reaction activity with a lithium source, and the prepared lithium cobalt oxide positive electrode material is relatively excellent in electrochemical performance.

The invention discloses cobaltosic oxide, a preparation method thereof, lithium cobalt oxide, a positive pole piece and a battery, and relates to the technical field of lithium battery positive pole materials. The Dv50 of the cobaltosic oxide, the grain size D (111) of the (111) crystal face and the specific surface area BET meet the following relation: 3.33 [mu] m < 3 > / g < = # imgabs0 # < = 6.90 [mu] m < 3 > / g, wherein the Dv50 of the cobaltosic oxide is 3-20 [mu] m. The cobaltosic oxide is obtained by pre-sintering and calcining cobalt carbonate with the crystallinity of 30%-80% and the median particle size Dv50 of 3-22 [mu] m; the reaction activity of the cobaltosic oxide and a lithium source is high, the mechanical property is good, the lithium ion diffusion rate of the obtained lithium cobalt oxide is high, and the specific capacity and the first charge-discharge efficiency are relatively high.

The present disclosure relates to the technical field of new energy. Provided are cobaltosic oxide and cobalt carbonate and preparation methods therefor, a positive electrode material and a lithium-ion battery. Cobalt carbonate and corresponding cobaltosic oxide secondary particles are integrally subjected to gradient doping with Al, and the Al doping amount of a core layer thereof is higher than that of a coating layer, such that the crystal structure stability of an LCO material is improved, and the cycle performance of a lithium cobaltate battery prepared from a sintered positive electrode material is improved. The cobaltosic oxide comprises a core layer and a coating layer that coats the core layer, wherein the content of cobalt is reduced layer by layer from inside to outside, such that the surface Co4+ content is reduced, the Co dissolution amount is decreased, and the safety performance can be improved. The core layer is a functional layer, takes up a large proportion by volume, has a high cobalt content, and can improve the capacity and the cycle performance; and the coating layer is a modified layer, coats the core layer and is very thin, and the total content of doping elements is increased in a gradient manner, such that the specific performance of the material can be improved, and the comprehensive performance of LCO can be improved.

The invention belongs to the field of preparation of nano materials, and discloses a CoP / Co (OH) 2 sea urchin-shaped heterojunction catalyst growing on foamed nickel and a preparation method and application of the CoP / Co (OH) 2 sea urchin-shaped heterojunction catalyst. Alkali cobalt carbonate (CoCH) is used as a precursor, a crystalline phase CoP substrate is generated through a low-temperature phosphating method, then the surface of the crystalline phase CoP substrate is uniformly coated with an amorphous Co (OH) 2 layer through an electro-deposition process, and the self-supporting phosphating / hydroxyl heterogeneous structure catalyst (CoP / Co (OH) 2) is successfully constructed. The obtained CoP / Co (OH) 2 shows excellent complete water splitting performance, and is benefited from the high-activity specific surface area (Cdl = 44.66 mF cm <-2 >) and the interface rapid electron conduction characteristic (Rct = 0.43 omega) of a heterogeneous structure; when two electrodes are assembled to fully decompose water, the cell voltage is only 1.780 V when the current density is 250 mA cm <-2 >, and after continuous operation is carried out for 24 hours, the performance is basically kept unchanged, and the voltage fluctuation ratio is lower than 0.5%. CoP / Co (OH) 2 is prepared into a 2 * 2cm < 2 > self-supporting electrode to construct AEMWE, only 2.08 V cell voltage is needed under the ultrahigh current density of 1A cm <-2 >, the AEMWE can stably run for 250 hours, the attenuation rate is 80 mu V h <-1 >, meanwhile, the hydrogen production efficiency is calculated to reach 96.2% through gas metering and Faraday law, and the engineering potential of the AEMWE in large-scale hydrogen production application is verified.

The invention discloses a material particle size monitoring method and system for basic cobalt carbonate production, and relates to the technical field of material particle size monitoring. Through a multi-mode sensing data fusion and intelligent decomposition algorithm, the particle size monitoring precision under the working conditions of high solid content and strong turbulence is remarkably improved; according to the method, physical constraint and a dynamic splitting mechanism are combined, seed crystal particles and abnormal secondary nucleation particles are effectively distinguished, and the problem that double peaks are misjudged as broad peaks in a traditional method is avoided; meanwhile, on the basis of a current reference threshold strategy of sliding window statistics, different batches and working condition changes are adaptively matched, the manual intervention requirement is reduced, stirring parameters are adjusted and quantified into a function of a dispersion uniformity index, the limitation of empirical control is broken through, frequency domain compensation and adaptive filtering design are additionally introduced, and the dispersion uniformity is improved. And the influence of complex interference sources such as bubbles and mechanical vibration is obviously inhibited.

The invention discloses an MOF-derived CoNiFe-LDH / CCH self-supporting electrode material and a preparation method thereof, and the preparation method comprises the steps: growing (1D) nano needle basic cobalt carbonate (CCH) on pretreated foamed nickel by adopting a hydrothermal method, and growing (3D) polyhedral ZIF-67 by taking CCH as a sacrificial template to obtain a ZIF-67 / CCH precursor; and carrying out chemical etching and ion exchange on nickel nitrate hexahydrate and ferrous sulfate heptahydrate to obtain the (2D) nanosheet coated CoNiFe-LDH / CCH self-supporting electrode material. The specific capacitance of the CoNiFe-LDH / CCH electrode material prepared under preferable conditions can reach 2856.6 F / g when the current density is 1 A / g, and a sample can keep 93.02% of the initial capacitance of the CoNiFe-LDH / CCH electrode material after 3000 times of cyclic charging and discharging. The method is environment-friendly, low in material cost and excellent in electrochemical performance, and has huge potential in practical application of supercapacitors.

The invention relates to high-aluminum-content basic cobalt carbonate and a preparation method thereof. The method comprises the following steps: 1) preparing a mixed solution from cobalt salt and aluminum salt; (2) adding a small amount of ammonium bicarbonate solution into a reaction kettle, starting heating, adding the mixed solution into the reaction kettle while stirring, controlling the pH value, and reacting to obtain a seed crystal dispersion liquid; and (3) adding the mixed solution and an ammonium bicarbonate solution into the seed crystal dispersion liquid, controlling the pH value, continuously reacting under heating and stirring until the particle size of the basic cobalt carbonate reaches a set value, stopping the reaction, and carrying out filter pressing, washing and drying to obtain the basic cobalt carbonate with high aluminum doping amount. The aluminum doping in the basic cobalt carbonate provided by the invention is as high as 7767-8357ppm, and the aluminum element is uniformly distributed and does not segregate.

The invention relates to composite-form aluminum-doped cobalt carbonate as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing a first carbonate solution, a second carbonate solution and an aluminum-doped cobalt salt solution; under the stirring condition, the aluminum-doped cobalt salt solution and the first carbonate solution are added into the second carbonate solution for a pre-reaction, and a reaction solution containing cobalt carbonate seed crystals is obtained; an aluminum-doped cobalt salt solution and a first carbonate solution are continuously added into the reaction solution, a first reaction and a second reaction are sequentially carried out, composite-form aluminum-doped cobalt carbonate particles are obtained, the second reaction comprises a first stage and a second stage, the mass ratio of the aluminum-doped cobalt salt solution to the first carbonate solution in the first stage is 1: 1-2: 1, and the mass ratio of the aluminum-doped cobalt salt solution to the second carbonate solution in the second stage is 1: 1-2: 1; and in the second stage, the mass ratio of the aluminum-doped cobalt salt solution to the first carbonate solution is (0.10: 1)-(0.25: 1). According to the preparation method disclosed by the invention, uniform dispersion of an outer-layer aluminum sheet is realized, and the uniformity of aluminum doping in cobalt carbonate is improved.

The invention relates to a coprecipitation method for preparing cobaltosic oxide, which comprises the following steps: mixing a cobalt salt solution, a precipitant solution and a complexing agent solution in a carbonate base solution in a parallel flow manner, and carrying out first coprecipitation reaction to a first particle size to obtain a seed crystal; the cobalt salt solution, the precipitant solution and the complexing agent solution are mixed in a parallel flow mode, a second coprecipitation reaction is conducted, and cobalt carbonate powder is obtained; calcining the cobalt carbonate powder to obtain cobaltosic oxide with a median particle size D50 of 18-20 [mu] m; a complexing agent in the complexing agent solution is iminodiacetic acid. According to the invention, by using the specific complexing agent, cobalt ions exist in the system in the form of complex ions and are slowly released in the reaction process, so that the first coprecipitation reaction can be carried out orderly, and the cobaltosic oxide with the median particle size D50 of 18-20 [mu] m can be obtained.

The invention provides spherical cobaltosic oxide as well as a preparation method and application thereof, the preparation method comprises the following steps: (1) injecting a cobalt salt-containing solution and a carbonate solution into a base solution in a parallel flow manner for a coprecipitation reaction to obtain a mixed-phase precursor; and (2) calcining the mixed phase precursor to obtain the spherical cobaltosic oxide, wherein the solute of the base solution in the step (1) is alkali metal hydroxide. According to the method disclosed by the invention, the precursor of the hydroxyl cobalt oxide and cobalt carbonate mixed phase can be prepared without separating kettles, the content of foreign ions in the precursor is low, and small-particle and high-purity cobaltosic oxide can be prepared by directly sintering.

The invention provides phase-inversion-free aluminum-doped cobalt carbonate and a preparation method thereof, a positive electrode material and a battery, the preparation method comprises the following steps: feeding an aluminum-containing first cobalt salt solution and a first precipitant solution into a reaction device, and carrying out a first precipitation reaction to obtain a first reacted material containing first solid-phase particles; introducing a second cobalt salt solution and a second precipitant solution into the first reaction post-material, and carrying out a second precipitation reaction to prepare aluminum-containing cobalt carbonate, so as to obtain a second reaction post-material containing second solid-phase particles; wherein the average particle size of the second solid-phase particles is 2-3 [mu] m larger than that of the first solid-phase particles. According to the method, the aluminum-containing first cobalt salt solution is firstly adopted for the first precipitation reaction, then the aluminum-free second cobalt salt solution is adopted for the second precipitation reaction, and the mass concentrations of cobalt in the two stages of reactions are controlled to be the same, so that the aluminum segregation phenomenon in the highly aluminum-doped precursor can be greatly reduced, and the material percent of pass is improved.

The invention provides a method for regulating and controlling the morphology of cobaltosic oxide and application thereof, and the method comprises the following steps: carrying out first mixing and reaction on a cobalt salt solution and an ammonium bicarbonate substance solution to obtain cobalt carbonate containing ammonium chloride; cobalt salt in the cobalt salt solution comprises chlorine-containing cobalt salt or chlorine-free cobalt salt, and when the cobalt salt in the cobalt salt solution is chlorine-free cobalt salt, ammonium chloride is also added during the first mixing; and carrying out secondary mixing and calcining on a macromolecular additive and the cobalt carbonate containing ammonium chloride to obtain the cobaltosic oxide with controllable morphology. According to the method, by introducing the additive, the additive adsorbs a specific crystal face and controls the crystal face growth of the cobaltosic oxide, so that the morphology of the cobaltosic oxide is accurately regulated and controlled, the dominant growth crystal face of the cobaltosic oxide can be controlled, the lithium matching sintering activity of the cobaltosic oxide during preparation of the lithium cobalt oxide is improved, and the preparation process is simple. Therefore, the performance of the lithium cobalt oxide material is further improved.

The present invention discloses a cobalt oxide and a preparation method thereof, lithium cobalt oxide, a positive electrode sheet and a battery, and relates to the technical field of positive electrode materials for lithium batteries. The Dv50, the grain size D(111) of the (111) crystal plane and the specific surface area BET of the cobalt oxide satisfy the following relationship: 3.33 g ‑1 ≤#imgabs0#≤6.90g ‑1 , wherein the Dv50 of the cobalt oxide is 3-20 μm. The cobalt oxide is obtained by pre-sintering and calcining cobalt carbonate with a crystallinity of 30%-80% and a median particle size Dv50 of 3-22 μm; the cobalt oxide has high reactivity with the lithium source and good mechanical properties, and the obtained lithium cobalt oxide has a high lithium ion diffusion rate, thereby having a high specific capacity and initial charge and discharge efficiency.

The invention provides high-aluminum doped cobalt carbonate and a preparation method and application thereof, and the preparation method comprises the following steps: (1) injecting a cobalt-aluminum mixed salt solution, a carbonate solution and an organic weak acid solution into a base solution in a parallel flow manner, and carrying out a co-precipitation reaction to obtain a precursor; and (2) stopping injection of the organic weak acid solution, continuing to inject the cobalt-aluminum mixed salt solution and the carbonate solution, and carrying out a co-precipitation reaction to obtain the high-aluminum doped cobalt carbonate. According to the method, through segmented coprecipitation and control of the types of precipitants used for coprecipitation of all the segments, the doping amount and uniformity of aluminum in cobalt carbonate can be improved, aluminum segregation is avoided, and meanwhile high-aluminum-doped cobalt carbonate higher in sphericity degree and better in compactness can be obtained.

The invention relates to an aluminum-zirconium co-doped cobaltosic oxide positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: a cobalt-aluminum mixed solution, a zirconium salt solution and a precipitator solution are introduced into an ammonium bicarbonate base solution in a parallel flow manner, and aluminum-zirconium co-doped cobalt carbonate is prepared by a clarification method; washing, drying, calcining and decomposing the obtained aluminum-zirconium co-doped cobalt carbonate to obtain an aluminum-zirconium co-doped precursor; mixing a lithium source with the aluminum-zirconium co-doped precursor to obtain a mixture; and sequentially carrying out heating heat treatment and heat preservation heat treatment on the mixture to obtain the aluminum-zirconium co-doped cobaltosic oxide positive electrode material, the preparation method provided by the invention comprises the following steps: uniformly doping Al < 3 + > and Zr < 2 + > into cobalt carbonate through specific steps, calcining and decomposing to obtain cobaltosic oxide with uniform granularity and uniform doping elements, then mixing the cobaltosic oxide with a lithium source, and carrying out heat treatment to obtain the aluminum-zirconium co-doped cobaltosic oxide positive electrode material with high capacity and stable cycle performance.

The present invention discloses a self-supporting oxygen evolution electrode and its preparation method and application, which belongs to the field of alkaline water electrolysis hydrogen production; the electrode is obtained by combining a hydrothermal method and an electrodeposition method; the electrode grows manganese-doped basic cobalt carbonate nanowires vertically on the surface of nickel foam, and the nanowires are surrounded by multiple layered nickel-iron double metal hydroxide nanosheets to form a nanorod as a whole. The nanorods are uniform in size, 2 to 3 μm long, and 100 to 500 nm in diameter, growing vertically on the surface of nickel foam; the electrode has high catalytic activity and stability. After using nickel foam as a conductive substrate, it can still operate stably for a long time under a high electrolysis current and in a strong alkaline medium; the electrode is used to catalyze the oxygen evolution reaction of water electrolysis to produce hydrogen under alkaline conditions; the present invention can be applied to renewable fuel cells, photoelectrocatalysis, alkaline anion exchange membrane water electrolysis (AEMWE) and electrolysis hydrogen generator devices.

The invention discloses an aluminum-magnesium co-doped cobalt carbonate precursor as well as a preparation method and application thereof. The preparation method comprises the following steps: respectively preparing a cobalt-aluminum mixed solution and a magnesium-containing precipitant solution; and adding the cobalt-aluminum mixed salt solution and the magnesium-containing precipitant solution into a base solution, and carrying out a co-precipitation reaction to obtain the aluminum-magnesium co-doped cobalt carbonate precursor. According to the method disclosed by the invention, the magnesium element is introduced into the precipitant solution in advance, so that magnesium ions can be complexed with the precipitant in advance, and the problems of nonuniform doping and segregation caused by difficult control of the precipitation rate of magnesium in the doping process are solved. According to the aluminum-magnesium co-doped cobalt carbonate precursor prepared by the method, magnesium and aluminum are uniformly doped, and the cycling stability of a lithium cobalt oxide battery can be effectively improved.

The application discloses a preparation method of a nickel-doped and high-hydrated cobalt-chromium-iron ore monocrystal under high temperature and high pressure, and the method comprises the following steps: preparing a cylindrical cobalt-chromium-iron ore sample by taking solid basic cobalt carbonate powder, solid chromium (III) acetate hydroxide crystal powder, solid nickel stearate, solid oxalic acid powder, solid chromium hydroxide powder, solid nickel hydroxide powder and liquid dilute nitric acid as starting raw materials; preparing water source sheets by taking chromium hydroxide powder and nickel hydroxide powder in a weight ratio of 4:1; placing two water source sheets at two ends of the cylindrical cobalt-chromium-iron ore sample respectively and then putting them into a double-capsule structure sample bin; and obtaining a cobalt-chromium-iron ore monocrystal after high-temperature and high-pressure reaction, so that the blank of the preparation technology of the nickel-doped and high-hydrated cobalt-chromium-iron ore large-grain monocrystal under the current high-temperature and high-pressure condition is solved, and the experimental sample of the nickel-doped and high-hydrated cobalt-chromium-iron ore large-grain monocrystal is obtained.

Provided is a method for separating impurities and cobalt without using an electrolysis process from a cobalt chloride solution containing impurities and producing a high purity cobalt sulfate. The production method for cobalt sulfate includes: a copper removal step (S1) of adding a sulfurizing agent to a cobalt chloride solution containing one or more impurities of copper, zinc, manganese, calcium, and magnesium and generating a precipitate of sulfide of copper to separate to remove copper; a neutralization step (S2) of adding a neutralizer or a carbonation agent to a cobalt chloride solution having undergone through the copper removal step (S1) and generating cobalt hydroxide or basic cobalt carbonate to separate magnesium; a leaching step (S3) of adding sulfuric acid to the cobalt hydroxide or the basic cobalt carbonate to obtain cobalt sulfate solution; and a solvent extraction step (S4) of bringing an organic solvent containing an alkyl phosphoric acid-based extractant to the cobalt sulfate solution and extracting zinc, manganese, and calcium into the organic solvent to separate to remove zinc, manganese, and calcium. These steps are sequentially executed.

The present disclosure relates to the technical field of battery material preparation, and in particular to a preparation method for a large-particle cobaltosic oxide, comprising the following steps: mixing a cobalt salt solution with a carbonate-containing precipitant solution A, performing solid-liquid separation after reaction, taking solid phase substances, and drying and crushing to obtain amorphous nano cobalt carbonate; mixing a cobalt salt solution with a carbonate-containing precipitant solution B and a carbonate-containing precipitant solution C, generating cobalt carbonate particles after reaction, then adding the amorphous nano cobalt carbonate for reaction to obtain a reaction solution containing a cobalt carbonate matrix coated with the amorphous nano cobalt carbonate; and adding a hydroxyl-containing precipitant solution D into the reaction solution, adding the cobalt salt solution and the precipitant solution D, generating mixed particles after reaction, then performing solid-liquid separation, taking solid phase substances to obtain a cobalt carbonate / cobalt hydroxide mixture, performing primary sintering and then mixing with the amorphous nano cobalt carbonate, and performing secondary sintering to obtain a large-particle cobaltosic oxide.

The invention discloses a preparation process of a high-activity supported cobalt-based catalyst in the technical field of thermocatalysis, which comprises the following steps: 1) precipitation reaction: in a hydrothermal precipitation reactor, adding a cetyl trimethyl ammonium bromide aqueous solution and urea into a 0-0.08 mol / L cobalt nitrate aqueous solution and a 0-0.008 mol / L manganese nitrate aqueous solution, and precipitating the urea and cobalt cations to generate cobalt hydroxide; 2) solid-liquid separation: carrying out solid-liquid separation on the material obtained in the previous step in solid-liquid separation equipment to obtain a solid-phase material which is a cobalt hydroxide crude product, and carrying out further impurity removal treatment to obtain a cobalt carbonate product; and 3) heat treatment: in heat treatment reaction equipment, carrying out heat treatment on the cobalt carbonate product obtained in the previous step to obtain a product with manganese oxide loaded on cobaltosic oxide, and realizing complete catalytic oxidation of carbon monoxide at room temperature, thereby reducing emission of carbon monoxide and realizing energy conservation and emission reduction.

The application belongs to the technical field of water electrolysis catalysts, and discloses a NiFe-based bifunctional water decomposition electrocatalyst, a preparation method and application thereof, the catalyst is a core-shell heterostructure, a three-dimensional self-supporting NiFe-based OER / HER bifunctional electrocatalyst, specifically, a coral spherical NiFe-LDH coated basic cobalt carbonate nanowire nanomaterial NiFe-LDH@Co-CH / NF with a three-dimensional hierarchical porous core-shell heterostructure; the catalyst is prepared by a two-step method of hydrothermal and solvothermal, and the foam nickel is used as a conductive substrate, the inner layer is the basic cobalt carbonate nanowire, and the outer layer is the NiFe-LDH nanosheet. The catalyst has excellent OER and HER performance, significantly accelerates the diffusion and transfer of the electrolyte solution, excites the synergistic effect and electron transfer, and improves the catalytic activity of the catalyst. The water electrolysis system assembled by the catalyst has excellent water electrolysis performance, and has a wide application prospect.

The application provides an aluminum-manganese-nickel co-doped cobalt carbonate precursor and a preparation method and use thereof. The preparation method comprises the following steps: mixing a cobalt-aluminum mixed salt solution, a manganese salt solution, a nickel salt solution and a precipitant solution, and performing a co-precipitation reaction to obtain the aluminum-manganese-nickel co-doped cobalt carbonate precursor; wherein the cobalt-aluminum mixed salt solution comprises a complexing agent; the manganese salt solution comprises a first surfactant and a second surfactant, the first surfactant comprises a crown ether surfactant, and the second surfactant comprises a non-ionic surfactant. The preparation method provided by the application realizes uniform doping of aluminum, manganese and nickel in the cobalt carbonate precursor material, not only reduces the risk of low capacity caused by only increasing the aluminum content, but also reduces the risk of small particle explosion in the reaction process, so that the obtained tricobalt tetraoxide precursor material has uniform particle size and uniform distribution of doped elements.

The invention discloses a saturation capacity recovery method of resin for removing ammonia nitrogen and chlorine radicals in cobalt carbonate wastewater, belongs to the field of ion exchange resin, and solves the problems that the saturation capacity of the resin is reduced and the service life is shortened. The method comprises the following steps: firstly, analyzing the saturated cation resin subjected to ammonia nitrogen removal adsorption by using ammonia water, so that anions adsorbed in the cation resin are thoroughly analyzed; then, pure water is used for flushing; ammonia nitrogen adsorbed on the cationic resin is desorbed by using hydrochloric acid; finally, pure water is used for flushing; the method comprises the following steps of: firstly, analyzing the anion resin which is saturated in chlorine ion removal adsorption by using hydrochloric acid, so that cations adsorbed in the anion resin are thoroughly analyzed; then, pure water is used for flushing; ammonia water is used for analyzing chloride ions adsorbed on the anion resin; finally, pure water is used for flushing. According to the method, the problem of incomplete analysis of a traditional method is solved, the saturation capacity recovery rate of the resin reaches 95% through periodic backwashing regeneration, and the service life of the resin is obviously prolonged.

This disclosure belongs to the technical field of battery positive electrode material preparation and discloses a method for preparing battery positive electrode material precursors using cobalt-iron slag. The method first involves roasting the cobalt-iron slag, acid leaching, and solid-liquid separation to produce molten iron and cobalt slag. The molten iron is then prepared into ferric phosphate dihydrate. The cobalt slag is then decontaminated to produce cobalt carbonate. Finally, calcination is performed to obtain ferric phosphate and cobalt trioxide. The ferric phosphate and cobalt oxide precursors prepared in this disclosure are both of high purity, and batteries prepared using them exhibit excellent chemical properties.

The invention discloses a cobalt carbonate material as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. The cobalt carbonate material comprises an outer layer area and an inner layer area located on the inner side of the outer layer area, the inner layer area refers to an area formed by extending from the particle center of the cobalt carbonate material to the particle surface by the distance of (0.67-0.76) r, and r refers to the radius of the cobalt carbonate material particle; the cobalt carbonate material has a diffraction peak of a (101) crystal face in an X-ray diffraction pattern; the ratio of the diffraction peak intensity of the (101) crystal face of the cobalt carbonate material to the diffraction peak intensity of the (101) crystal face of the inner layer region is x1, and x1 is greater than 1.7; the cobalt carbonate material comprises a cobalt carbonate matrix and a nickel element doped into the cobalt carbonate matrix, and the phenomena of breaking, powder floating and the like during subsequent sintering preparation of the high-nickel-doped cobaltosic oxide material are avoided.

The present invention provides a method for preparing high-density small-particle cobalt carbonate, prepares a cobalt salt solution and an ammonium bicarbonate solution, adds them to a reaction vessel in a continuous feeding manner and reacts; in the initial stage of the continuous feeding stage, stops feeding at intervals and performs aging treatment, and continues to react after several agings until the seed crystal grows to a certain particle size; stops settling, siphons the supernatant, and then adopts a one-time feeding method to add the reaction solution to the reaction vessel, and continues to react under closed conditions to obtain a cobalt carbonate slurry; after washing, separation and drying, a high-density small-particle cobalt carbonate is obtained. The present invention is regularly aged at the initial stage of the reaction, effectively improving the defects of the seed crystal such as loose structure and poor density in the generation stage; adopts a combination of a continuous feeding method and a one-time feeding method, and in the crystal growth stage, the reaction time is effectively shortened by a one-time feeding, the production efficiency is improved, and the density and particle size consistency of the particles are further improved.

The invention discloses cobalt carbonate, a preparation method and application, the cobalt carbonate comprises a cobalt carbonate inner core and an aluminum-doped cobalt carbonate coating layer coating the cobalt carbonate inner core, and the pore volume of the cobalt carbonate inner core is smaller than that of the cobalt carbonate. The cobalt carbonate in the application has a synergistic effect between a gradient pore structure and gradient aluminum doping distribution, so that the problem that cobalt carbonate particles are easy to crack and remove powder during sintering is solved, the sintered cobaltosic oxide can be kept to have relatively excellent tap density and mechanical strength, and the electrochemical performance of lithium cobalt oxide is further improved.

The invention provides basic cobalt carbonate with high carbonate content and a preparation method thereof, and belongs to the technical field of cobalt compound preparation. The basic cobalt carbonate can be used as a cobalt source or a cobalt compound precursor for a positive electrode material. The method comprises the following steps: introducing carbon dioxide into a sodium carbonate solution in advance to obtain a pre-carbonized sodium carbonate solution; synchronously dropwise adding the pre-carbonized sodium carbonate solution and the cobaltous sulfate solution for reaction under the condition of partial pressure of carbon dioxide, and controlling the pH value of the reaction solution to obtain reaction slurry; aging the reaction slurry under a carbon dioxide pressurization condition, regulating the pH value, and filtering to obtain a wet filter cake; the wet filter cake is sequentially subjected to sodium bicarbonate solution replacement washing and carbon dioxide saturated deionized water washing, then dried, smashed and screened, and a product is obtained; the method disclosed by the invention is beneficial to improving the carbonate introduction degree of basic cobalt carbonate and reducing soluble salt entrainment, and few insoluble residues are generated in acid medium dissolution evaluation.

The invention discloses an HER electrocatalyst with a porous heterostructure and a preparation method of the HER electrocatalyst, and belongs to the field of HER electrocatalysts.The preparation method comprises the following steps that cobalt nitrate hexahydrate, urea, foamed nickel and ruthenium chloride serve as raw materials, and a Ru-doped basic cobalt carbonate nanowire array is prepared through a solvothermal method; the Ru doped basic cobalt carbonate nanowire array is heated in a muffle furnace, and a RuO2 / Co3O4 nanowire array is obtained; the RuO2 / Co3O4 nanowire array and NaH2PO2 are placed in a crucible, annealing and phosphorization are carried out in nitrogen gas flow, a RuO2 / CoxP / Co3O4 nanowire array is obtained, then acid pickling is carried out to remove Co3O4, the RuO2 / CoxP nanowire array is obtained, and the HER electrocatalyst with the porous heterostructure is obtained.