WO2024040901A1 - 一种转晶掺铝碳酸钴的制备方法和应用 - Google Patents

一种转晶掺铝碳酸钴的制备方法和应用 Download PDF

Info

Publication number
WO2024040901A1
WO2024040901A1 PCT/CN2023/078766 CN2023078766W WO2024040901A1 WO 2024040901 A1 WO2024040901 A1 WO 2024040901A1 CN 2023078766 W CN2023078766 W CN 2023078766W WO 2024040901 A1 WO2024040901 A1 WO 2024040901A1
Authority
WO
WIPO (PCT)
Prior art keywords
aluminum
ammonium bicarbonate
bicarbonate solution
cobalt carbonate
solution
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2023/078766
Other languages
English (en)
French (fr)
Inventor
卢星华
李长东
阮丁山
刘更好
周思源
王永平
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hunan Brunp Recycling Technology Co Ltd
Guangdong Brunp Recycling Technology Co Ltd
Original Assignee
Hunan Brunp Recycling Technology Co Ltd
Guangdong Brunp Recycling Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hunan Brunp Recycling Technology Co Ltd, Guangdong Brunp Recycling Technology Co Ltd filed Critical Hunan Brunp Recycling Technology Co Ltd
Publication of WO2024040901A1 publication Critical patent/WO2024040901A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G51/00—Compounds of cobalt
    • C01G51/06—Carbonates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/03—Particle morphology depicted by an image obtained by SEM
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/12—Surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the invention belongs to the technical field of lithium-ion battery materials, and particularly relates to a preparation method and application of transcrystalline aluminum-doped cobalt carbonate.
  • Lithium cobalt oxide cathode material is mainly used in the 3C field due to its high energy density.
  • High-voltage lithium cobalt oxide can have higher capacity, but its structure is easy to collapse during cycling.
  • a certain amount of aluminum element is usually doped into the cobalt tetroxide precursor.
  • aluminum may exist in the form of amorphous aluminum carbonate, crystalline aluminum hydroxide or crystalline basic aluminum ammonium carbonate and other compounds.
  • the reaction conditions are usually controlled, and aluminum is doped into cobalt carbonate particles in the form of amorphous aluminum carbonate.
  • this type of material is extremely unstable and prone to occur during the washing and drying processes of the product. Hydrolysis and recrystallization lead to poor aluminum doping effect and the occurrence of aluminum segregation, which affects the cycle performance of aluminum-doped cobalt carbonate.
  • the present invention aims to solve at least one of the technical problems existing in the prior art.
  • the present invention proposes a preparation method and application of transcrystalline aluminum-doped cobalt carbonate.
  • the transcrystalline aluminum-doped cobalt carbonate prepared by the preparation method of transcrystalline aluminum-doped cobalt carbonate has a good aluminum-doping effect, thereby ensuring that the doping effect is Aluminum cobalt carbonate has good cycle performance.
  • a method for preparing transcrystalline aluminum-doped cobalt carbonate including the following steps:
  • (1) Prepare cobalt salt and aluminum salt into a mixed metal solution, and prepare a first ammonium bicarbonate solution, a second ammonium bicarbonate solution and a third ammonium bicarbonate solution, wherein the concentration of the first ammonium bicarbonate solution is 0.8-1.6mol/L, the concentration of the second ammonium bicarbonate solution is 2.5-3.0mol/L, and the concentration of the third ammonium bicarbonate solution is 1.5-2.0mol/L;
  • step (3) Add the mixed metal solution and the third ammonium bicarbonate solution to the solution containing the transformed aluminum-cobalt carbonate seed crystal obtained in step (2) in parallel flow, mix and react until the crystallized
  • the particle size of the aluminum-doped cobalt carbonate seed crystal is grown to 16.0-19.0 ⁇ m, the solid and liquid are separated, and the obtained solid is washed and dried to obtain the trans-crystalline aluminum-doped cobalt carbonate.
  • the concentration of cobalt ions in the mixed metal solution is 1.5-2.5 mol/L, and the molar ratio of aluminum element to cobalt element is 0.001-0.01.
  • step (1) in the mixed metal solution, the concentration of cobalt ions is 1.5-2.2 mol/L, and the molar ratio of aluminum element to cobalt element is 0.005-0.01.
  • the cobalt salt is at least one of cobalt sulfate, cobalt nitrate or cobalt chloride.
  • the aluminum salt is at least one of aluminum sulfate, aluminum chloride or aluminum nitrate.
  • step (2) the reaction of step (2) and step (3) is carried out in a reaction kettle.
  • step (2) the first ammonium bicarbonate solution is first added into the reaction kettle as the bottom liquid and the temperature is raised. Under stirring, add the mixed metal solution and the second ammonium bicarbonate solution in parallel flow through the liquid adding pipe to react.
  • the liquid level in the reaction kettle reaches the set value, start the concentration and monitor the generated seed crystals. The specific surface area of the seed crystal reaches the target value.
  • the bottom liquid accounts for 20%-30% of the total volume of the reaction kettle
  • the flow rate of the mixed metal solution is 200-300L/h
  • the flow rate of the second ammonium bicarbonate solution is is 100-150L/h.
  • the pH of the reaction in step (2) is controlled to be 7.0-8.5.
  • the pH of the reaction in step (2) is controlled to be 7.0-7.5.
  • step (3) on the premise that concentration is turned on, the mixed metal solution and the third ammonium bicarbonate solution are added in parallel flow through a liquid adding pipe, and the flow rate of the mixed metal solution is 100-200L/h. , by continuously adding the third ammonium bicarbonate solution to control the pH of the reaction to 7.8-8.2, and stabilizing the liquid level in the kettle at 80%-85% of the total volume, the mixed metal solution, the second ammonium bicarbonate solution The size of the liquid adding tube used for the solution and the third ammonium bicarbonate solution is the same.
  • the reaction temperature is raised to 60-80°C at a temperature rise rate of 10-30°C/h.
  • step (3) the reaction temperature is raised to 65-70°C at a heating rate of 20-30°C/h.
  • the number of liquid adding tubes for the mixed metal solution described in step (3) is greater than the number of liquid adding tubes for the mixed metal solution described in step (2), and the number of the third ammonium bicarbonate solution described in step (3) is The number of liquid adding tubes is greater than the number of liquid adding tubes for the second ammonium bicarbonate solution described in step (2).
  • the number of liquid adding pipes for the mixed metal solution and the second ammonium bicarbonate solution in step (2) is one.
  • the obtained materials are also screened and packaged.
  • the mesh size of the sieve is 300-500 mesh, such as 400 mesh.
  • the temperature of the water used for washing in step (3) is 60-100°C, and the washing time is 20-100 minutes.
  • the temperature of the water used for washing in step (3) is 80-100°C, and the washing time is 30-60 minutes.
  • the drying temperature in step (3) is 100-150°C, and the moisture in the material after drying is less than 5%.
  • the drying temperature in step (3) is 120-130°C, and the moisture in the material after drying is less than 1%.
  • transcrystalline aluminum-doped cobalt carbonate prepared by the above preparation method in preparing lithium cobalt oxide cathode material.
  • the present invention maintains a lower temperature of 40-45°C during seed crystal synthesis, which can slow down the precipitation rate of aluminum and make aluminum doped in cobalt carbonate in the form of amorphous aluminum carbonate, which is beneficial to the uniform distribution of aluminum; at the same time
  • aluminum-doped cobalt carbonate particles with a low specific surface area of 0.3-0.6cm 2 /g as transcrystallized cobalt carbonate seeds there are abundant surface defects on the surface.
  • the peak-shaped primary particles are more prominent and the gaps between the primary particles are also relatively large.
  • the present invention uses a single metal liquid adding pipe and a single ammonium bicarbonate solution adding pipe during the preparation of seed crystals, which can increase the supersaturation at the moment of feeding and generate more crystal nuclei; while in the cobalt carbonate crystal form During the transformation and growth process, the number of liquid adding tubes for the metal liquid and the ammonium bicarbonate solution is increased respectively. When the total amount of liquid input remains unchanged, the instant supersaturation of the feed can be reduced, avoid the generation of small particles, and at the same time can Accelerates the decomposition of ammonium bicarbonate solution.
  • aluminum is doped into cobalt carbonate in the form of amorphous aluminum carbonate during the seed crystal synthesis, and during the crystal form transformation and growth stages of cobalt carbonate, a higher synthesis temperature is used to achieve a faster heating rate.
  • lower concentration of ammonium bicarbonate solution and multiple ammonium bicarbonate solution filling pipes enable ammonium bicarbonate to decompose more hydroxide ions, quickly increase the concentration of hydroxide ions in the reaction system, and reduce the concentration of carbonate ions , causing a sudden change in the concentration of each ion in the synthesis system, providing sufficient driving force for crystallization, and transforming the newly generated aluminum-doped cobalt carbonate crystal form.
  • the transformed lamellar crystal form of basic cobalt aluminum carbonate has rich surfaces. Stacked growth is established on the defective crystal seeds; if the temperature rise rate is slow during the regulation of the crystal transformation of cobalt carbonate and the temperature does not rise to a certain range or the concentration of ammonium bicarbonate is high, that is, the concentration of carbonate ions in the system is high, the alkali Formula cobalt aluminum carbonate is difficult to generate, so no obvious crystalline mutation will occur; by maintaining a higher reaction pH value, the phase components of basic cobalt aluminum carbonate can be further increased to achieve the purpose of complete crystallization of aluminum-doped cobalt carbonate.
  • Figure 1 is an SEM image of a transformed aluminum-doped cobalt carbonate seed crystal in Example 1 of the present invention
  • Figure 2 is an SEM image of the finished product of crystallized aluminum-doped cobalt carbonate in Example 1 of the present invention
  • Figure 3 is an XRD pattern of the finished product of crystallized aluminum-doped cobalt carbonate in Example 1 of the present invention
  • Figure 4 is an SEM image of a transformed aluminum-doped cobalt carbonate seed crystal in Example 2 of the present invention.
  • Figure 5 is an SEM image of the finished product of crystallized aluminum-doped cobalt carbonate in Example 2 of the present invention.
  • Figure 6 is an SEM image of the finished product of crystallized aluminum-doped cobalt carbonate in Example 3 of the present invention.
  • Figure 7 is an SEM image of the finished cobalt doped with aluminum carbonate in Comparative Example 1 of the present invention.
  • Figure 8 is an SEM image of the aluminum-doped cobalt carbonate seed crystal of Comparative Example 2 of the present invention.
  • Figure 9 is an SEM image of the finished product of aluminum-doped cobalt carbonate in Comparative Example 2 of the present invention.
  • Figure 10 is an SEM image of the finished product of aluminum-doped cobalt carbonate in Comparative Example 3 of the present invention.
  • Figure 11 is an SEM image of the finished product of aluminum-doped cobalt carbonate in Comparative Example 4 of the present invention.
  • a method for preparing transcrystalline aluminum-doped cobalt carbonate including the following steps:
  • the flow rate is constant at a stable pH value of 7.50.
  • the concentration is started.
  • the mixed metal solution and the second ammonium bicarbonate solution are continuously introduced to keep the liquid level in the kettle stable at the total volume. 83%.
  • the measured BET of the seed crystal sample is 0.35cm 2 /g, the synthesis of the transferred crystallized aluminum-doped cobalt carbonate seed crystal is completed.
  • the SEM image of the obtained transferred crystallized aluminum-doped cobalt carbonate seed crystal is shown in Figure 1.
  • the measured D50 is 8.6 ⁇ m.
  • Cobalt carbonate crystal form transformation and growth Raise the reaction temperature to 65°C, control the heating rate of the reactor at 20°C/h, add the mixed metal solution and the third ammonium bicarbonate solution in parallel, and start concentration, in which the mixture Both the metal solution and the third ammonium bicarbonate solution are fed into the liquid at the same time through three liquid adding pipes.
  • the liquid adding pipes used to mix the metal solution, the second ammonium bicarbonate solution and the third ammonium bicarbonate solution are of the same size, among which the mixed metal solution
  • the flow rate is 200L/h.
  • the third ammonium bicarbonate solution is adjusted through the PLC control system to keep the pH value at 8.0 during the seed growth stage.
  • the mixed metal solution and the third ammonium bicarbonate solution are continuously introduced and the liquid level in the kettle is maintained.
  • the cobalt ion concentration in the mother liquor is 40 mg/L during the reaction, and when the particle size grows to 16.7 ⁇ m, a transcrystallized aluminum-doped cobalt carbonate slurry is obtained;
  • the XRD pattern of the obtained finished product of transformed crystallized aluminum-doped cobalt carbonate is as follows: As shown in Figure 3, the D50 is 16.7 ⁇ m and the aluminum element content is 4820ppm. From Figure 2, it can be seen that the primary particles are flake-shaped and there is no aluminum segregation. From Figure 3, it can be seen that the obtained transcrystallized aluminum-doped cobalt carbonate product is cobalt carbonate. and basic cobalt aluminum carbonate mixture.
  • a method for preparing transcrystalline aluminum-doped cobalt carbonate including the following steps:
  • the concentration of cobalt in the mixed metal solution is 2.2 mol/L
  • the molar ratio of aluminum and cobalt elements is 0.008
  • the concentration of the first ammonium bicarbonate solution is 0.8mol/L
  • the concentration of the second ammonium bicarbonate solution is 2.8mol/L
  • the concentration of the third ammonium bicarbonate solution is 1.7mol /L;
  • the flow rate is set at a stable pH value of 7.40.
  • concentration is started.
  • the mixed metal solution and ammonium bicarbonate A solution are continuously introduced and the liquid level in the kettle is kept stable at 80% of the total volume.
  • the measured BET of the seed crystal sample is 0.41cm 2 /g, the synthesis of the transferred crystallized aluminum-doped cobalt carbonate seed crystal is completed.
  • the obtained SEM image of the transferred crystallized aluminum-doped cobalt carbonate seed crystal is shown in Figure 4, and the measured D50 is 10.5 ⁇ m, as can be seen from Figure 4, the primary particles are massive and have no aluminum segregation;
  • the mixed metal solution and the third ammonium bicarbonate solution are continuously fed into and maintained in the kettle. The position is stabilized at 80% of the total volume.
  • the cobalt ion concentration in the mother liquor is 20 mg/L.
  • the particle size grows to 18.8 ⁇ m, a transcrystallized aluminum-doped cobalt carbonate slurry is obtained;
  • a method for preparing transcrystalline aluminum-doped cobalt carbonate including the following steps:
  • the concentration of cobalt in the mixed metal solution is 1.5 mol/L
  • the molar ratio of aluminum and cobalt elements is 0.005
  • the concentration of the first ammonium bicarbonate solution is 1.6mol/L
  • the concentration of the second ammonium bicarbonate solution is 2.5mol/L
  • the concentration of the third ammonium bicarbonate solution is 1.5mol /L;
  • the flow rate of the second ammonium bicarbonate solution is adjusted through the PLC control system to stabilize the pH value at 7.60.
  • the liquid level in the reaction kettle reaches 85% of the total volume % Turn on concentration, during concentration The mixed metal solution and the second ammonium bicarbonate solution are continuously introduced and the liquid level in the kettle is kept stable at 85% of the total volume.
  • the BET measured on the seed crystal sample is 0.56cm 2 /g, the crystal transfer is completed to the aluminum-doped cobalt carbonate seed crystal. Synthesized, the measured D50 is 12.5 ⁇ m, the primary particles are massive, and there is no aluminum segregation;
  • the mixed metal solution and the third ammonium bicarbonate solution are continuously fed into and maintained in the kettle. The position is stabilized at 85% of the total volume.
  • the cobalt ion concentration in the mother liquor is 50 mg/L.
  • the particle size grows to 17.5 ⁇ m, a transcrystallized aluminum-doped cobalt carbonate slurry is obtained;
  • a preparation method of aluminum-doped cobalt carbonate including the following steps:
  • the mixed metal solution and the third ammonium bicarbonate solution are continuously introduced and maintained
  • the liquid level in the kettle is stable at 83% of the total volume.
  • the cobalt ion concentration in the mother liquor is 150 mg/L.
  • the particle size grows to 16.6 ⁇ m, an aluminum-doped cobalt carbonate slurry is obtained;
  • a preparation method of aluminum-doped cobalt carbonate including the following steps:
  • a preparation method of aluminum-doped cobalt carbonate including the following steps:
  • the mixed metal solution and the third ammonium bicarbonate solution are continuously introduced and the liquid level in the kettle is kept stable at 83% of the total volume.
  • the mother liquor The cobalt ion concentration is 150 mg/L, and when the particle size grows to 16.7 ⁇ m, an aluminum-doped cobalt carbonate slurry is obtained;
  • a preparation method of aluminum-doped cobalt carbonate including the following steps:
  • the concentration of cobalt in the mixed metal solution is 2.0 mol/L
  • the molar ratio of aluminum to cobalt elements is 0.01
  • the concentration of the first ammonium bicarbonate solution is 1.0 mol/L
  • the concentrations of the second ammonium bicarbonate solution and the third ammonium bicarbonate solution are both 3 mol/L;
  • Cobalt carbonate crystal form transformation and growth Raise the reaction temperature to 65°C, control the heating rate of the reactor at 20°C/h, add the mixed metal solution and the third ammonium bicarbonate solution in parallel, and start concentration, in which the mixture
  • the metal liquid and the third ammonium bicarbonate solution are fed into the liquid at the same time through a single liquid adding pipe.
  • the liquid adding pipes used to mix the metal solution, the second ammonium bicarbonate solution and the third ammonium bicarbonate solution are of the same size.
  • the flow rate of the mixed metal solution is 200L/h
  • the third ammonium bicarbonate solution is adjusted through the PLC control system to keep the pH value at 8.0 during the seed growth stage.
  • the mixed metal solution and the third ammonium bicarbonate solution are continuously introduced and the liquid level in the kettle is kept stable at The total volume is 83%.
  • the cobalt ion concentration in the mother liquor is 40 mg/L.
  • Example 1 and Comparative Example 1 it can be concluded that the flake-shaped basic cobalt aluminum carbonate formed after crystallization not only ensures the uniformity of aluminum distribution during the synthesis process, but also avoids The aluminum flakes precipitated during the post-processing of the finished product; by comparing Example 1 and Comparative Example 2, it can be concluded that the seed crystal with a larger specific surface area cannot undergo crystal transformation under the growth conditions of high temperature and high pH, and the primary particles still inherit the crystal kind of massive morphology, and become coarser as the particles grow; by comparing Example 1 and Comparative Example 3, it can be concluded that during the crystal transformation and growth stages of cobalt carbonate, the slower heating rate and lower temperature, The particles failed to completely crystallize, and the primary particles were in the form of coarse lumps and flakes, and the surface consistency of the particles was poor.
  • Example 1 By comparing Example 1 and Comparative Example 4, it can be concluded that during the crystal transformation and growth stages of aluminum-doped cobalt carbonate, the use of crystallization The same concentration of ammonium bicarbonate and the method of adding liquid through a single liquid adding pipe in this preparation stage will still keep the concentration of carbonate ions in the mother liquor at a high value, and particle crystallization cannot occur.
  • the cobalt carbonate precursor prepared in the above Examples 1-3 and Comparative Examples 1-4 was calcined in a box furnace at 700°C for 4 hours, and then prepared into a battery according to the same conditions for electrochemical testing.
  • the general method is: combine the precursor with The lithium cobalt oxide material prepared by mixing and sintering lithium carbonate according to a certain proportion is used as the positive electrode, graphite is used as the negative electrode, and lithium hexafluorophosphate is used as the electrolyte to make a button battery.
  • the electrochemical test voltage is 4.55V.
  • a 1C high-temperature cycle test is performed at a temperature of 45°C. The results are shown in Table 1 below:
  • the aluminum-doped precursor after crystallization prepared in each embodiment is prepared into cobalt acid. After lithium, it is more conducive to the insertion of lithium and has excellent cycle performance. Its 50-cycle cycle retention rate can reach more than 90.6%, and its 80-cycle cycle retention rate can reach more than 81.5%.
  • the untransformed aluminum-doped aluminum prepared in the comparative example Due to the uneven distribution of aluminum in the precursor, the high-temperature cycle performance of the lithium cobalt oxide material is poor.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本发明公开了一种转晶掺铝碳酸钴的制备方法，包括以下步骤：（1）将钴盐、铝盐配制成混合金属溶液，并配制第一碳酸氢铵溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液；（2）将混合金属溶液与第二碳酸氢铵溶液并流加入到第一碳酸氢铵溶液中混合进行反应，并控制反应温度为40-45℃，直至生成比表面积为0.3-0.6cm2/g的转晶掺铝碳酸钴晶种；（3）向步骤（2）得到的含转晶掺铝碳酸钴晶种的溶液中并流加入混合金属溶液与第三碳酸氢铵溶液混合进行反应，直至转晶掺铝碳酸钴晶种的粒度生长至16.0-19.0μm，固液分离，并对得到的固体物进行洗涤、烘干，得到转晶掺铝碳酸钴。该转晶掺铝碳酸钴的制备方法制备得到的转晶掺铝碳酸钴具有较好的掺铝效果。

Description

一种转晶掺铝碳酸钴的制备方法和应用 技术领域
本发明属于锂离子电池材料技术领域，特别涉及一种转晶掺铝碳酸钴的制备方法和应用。
背景技术
钴酸锂正极材料由于其能量密度高的优点，主要应用在3C领域。高电压钴酸锂可以具有更高的容量，但在循环过程中其结构易坍塌，为了提高其循环性能，通常会在四氧化三钴前驱体中掺杂一定量的铝元素。
在掺铝碳酸钴制备过程中，铝的存在形式可能为无定型碳酸铝、晶型氢氧化铝或晶型碱式碳酸铝铵等化合物。为了保证铝掺杂的均匀性，通常会控制反应条件，将铝以无定型碳酸铝的形式掺杂在碳酸钴颗粒中，但该类物质极不稳定，在产品的洗涤和干燥工序中易发生水解和重结晶，导致掺铝效果不佳，出现铝偏析物的现象，影响掺铝碳酸钴的循环性能。
发明内容
本发明旨在至少解决现有技术中存在的技术问题之一。为此，本发明提出一种转晶掺铝碳酸钴的制备方法和应用，该转晶掺铝碳酸钴的制备方法制备得到的转晶掺铝碳酸钴具有较好的掺铝效果，从而保证掺铝碳酸钴具有较好的循环性能。
本发明的上述技术目的是通过以下技术方案得以实现的：
一种转晶掺铝碳酸钴的制备方法，包括以下步骤：
(1)将钴盐、铝盐配制成混合金属溶液，并配制第一碳酸氢铵溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液，其中所述第一碳酸氢铵溶液的浓度为0.8-1.6mol/L，所述第二碳酸氢铵溶液的浓度为2.5-3.0mol/L，所述第三碳酸氢铵溶液的浓度为1.5-2.0mol/L；
(2)将所述混合金属溶液与所述第二碳酸氢铵溶液并流加入到所述第一碳酸氢铵溶液中混合进行反应，并控制反应温度为40-45℃，直至生成比表面积为0.3-0.6cm2/g的转晶掺铝碳酸钴晶种；
(3)向步骤(2)得到的含所述转晶掺铝碳酸钴晶种的溶液中并流加入所述混合金属溶液与所述第三碳酸氢铵溶液混合进行反应，直至所述转晶掺铝碳酸钴晶种的粒度生长至16.0-19.0μm，固液分离，并对得到的固体物进行洗涤、烘干，得到所述转晶掺铝碳酸钴。
优选的，步骤(1)中，所述混合金属溶液中，钴离子的浓度为1.5-2.5mol/L，铝元素与钴元素的摩尔比为0.001-0.01。
进一步优选的，步骤(1)中，所述混合金属溶液中，钴离子的浓度为1.5-2.2mol/L，铝元素与钴元素的摩尔比为0.005-0.01。
优选的，步骤(1)中，所述钴盐为硫酸钴、硝酸钴或氯化钴中的至少一种。
优选的，步骤(1)中，所述铝盐为硫酸铝、氯化铝或硝酸铝中的至少一种。
优选的，步骤(2)和步骤(3)的反应是在反应釜中进行，步骤(2)中，先将所述第一碳酸氢铵溶液作为底液加入到所述反应釜中并升温，在搅拌状态下通过加液管并流加入所述混合金属溶液与所述第二碳酸氢铵溶液进行反应，当所述反应釜中的液位达到设定值时开启浓缩，监控生成的晶种的比表面积，直至所述晶种的比表面积达到目标值。
优选的，步骤(2)中，所述底液占所述反应釜总体积的20％-30％，所述混合金属溶液流量为200-300L/h，所述第二碳酸氢铵溶液的流量为100-150L/h，当所述反应釜中的液位达到所述反应釜总体积的80％-85％时开启浓缩，并持续通入所述混合金属溶液与所述第二碳酸氢铵溶液使釜内液位稳定在总体积80％-85％。
优选的，步骤(2)中控制反应的pH为7.0-8.5。
进一步优选的，步骤(2)中控制反应的pH为7.0-7.5。
优选的，步骤(3)中，在开启浓缩的前提下通过加液管并流加入所述混合金属溶液与所述第三碳酸氢铵溶液，所述混合金属溶液的流量为100-200L/h，通过持续加入所述第三碳酸氢铵溶液控制反应的pH为7.8-8.2，并使釜内液位稳定在总体积80％-85％，所述混合金属溶液、所述第二碳酸氢铵溶液和所述第三碳酸氢铵溶液用到的所述加液管的尺寸相同。优选的，步骤(3)中，以10-30℃/h的升温速度将反应温度升至60-80℃。
进一步优选的，步骤(3)中，以20-30℃/h的升温速度将反应温度升至65-70℃。
优选的，步骤(3)中所述混合金属溶液的加液管数量多于步骤(2)中所述混合金属溶液的加液管数量，步骤(3)中所述第三碳酸氢铵溶液的加液管数量多于步骤(2)中所述第二碳酸氢铵溶液的加液管数量。
优选的，步骤(2)中所述混合金属溶液和所述第二碳酸氢铵溶液的加液管数量均为一条。
优选的，步骤(3)中烘干后还对得到的物料进行了过筛和包装处理。
优选的，过筛的目数为300-500目，例如400目。
优选的，步骤(3)中洗涤用到的水的温度为60-100℃，洗涤时间为20-100min。
进一步优选的，步骤(3)中洗涤用到的水的温度为80-100℃，洗涤时间为30-60min。
优选的，步骤(3)中烘干的温度为100-150℃，烘干后物料中的水分低于5％。
进一步优选的，步骤(3)中烘干的温度为120-130℃，烘干后物料中的水分低于1％。
如上所述的制备方法制备的转晶掺铝碳酸钴在制备钴酸锂正极材料中的应用。
本发明的有益效果是：
(1)本发明在晶种合成期间保持40-45℃的较低温度，可以减缓铝的沉淀速度，使铝以无定型碳酸铝的形式掺杂在碳酸钴中，有利于铝均匀分布；同时通过制备0.3-0.6cm2/g低比表面积的掺铝碳酸钴颗粒作为转晶碳酸钴晶种，其表面存在丰富的面缺陷，山峰状的一次颗粒较突出，一次颗粒之间的空隙也较大，为片状晶型碳酸钴的二次形核提供充足生长位点，使片状晶型先在空隙内稳固生长并逐渐覆盖整个颗粒表面，达到碳酸钴转晶的目的；若晶种的比表面积偏大，颗粒表面缺陷少，山峰状一次颗粒排列密集，一次颗粒之间空隙变小，颗粒表面较为光滑，片状晶型难以稳固生长，新生成的碳酸钴晶粒更倾向于在原有山峰状的一次颗粒上生长，故难以达到碳酸钴晶型完全转变的目的。
(2)本发明在晶种制备期间使用单条金属加液管和单条碳酸氢铵溶液加液管，可以增大进料瞬间的过饱和度，生成更多的晶核；而在碳酸钴晶型转变及生长过程中分别将金属液和碳酸氢铵溶液的加液管数量增加，在进液总量不变的情况下可以减小进料瞬间的过饱和度，避免小颗粒的生成，同时可以加速碳酸氢铵溶液的分解。
(3)本发明在晶种合成期间将铝以无定型碳酸铝的形式掺杂在碳酸钴中，而在碳酸钴晶型转变及生长的阶段通过使用较高的合成温度，较快的升温速率，较低的碳酸氢铵溶液浓度和多条碳酸氢铵溶液加液管，使碳酸氢铵分解出更多的氢氧根离子，快速提高反应体系中氢氧根离子浓度，降低碳酸根离子浓度，使合成体系各离子浓度发生突变，为转晶提供足够的驱动力，使新生成的掺铝碳酸钴晶型发生转变，转变后的碱式碳酸钴铝的片状晶型在具有丰富的面缺陷的晶种上树立堆叠生长；若在调控碳酸钴晶型转变期间升温速度较慢且温度没有升高到一定范围或者碳酸氢铵浓度较高，即体系中碳酸根离子浓度较高，则碱式碳酸钴铝难以生成，就不会发生明显的晶型突变；通过维持较高的反应pH值，能够进一步增加碱式碳酸钴铝的相的组分，达到掺铝碳酸钴完全转晶的目的，使转晶的过程不可逆；从化学式： 6CoCl2+Al2(SO4)3+20H2O+18NH4HCO3＝Co6Al2CO3(OH)16·4H2O↓+3(NH4)2SO4+12NH4Cl+17H2CO3能看出碱式碳酸钴铝能够将铝离子和钴离子稳定共沉淀，使铝更容易掺杂在碳酸钴的晶格中，能够提高铝分布的均匀性，且该结晶产物更加稳定，方便后续更有利于锂的嵌入，保证电池具有较好的循环性能，同时高温下合成可以加快反应速率，提高钴的沉淀率，母液中钴含量稳定在50ppm以下，节省了废水处理成本。
附图说明
图1为本发明实施例1转晶掺铝碳酸钴晶种的SEM图；
图2为本发明实施例1转晶掺铝碳酸钴成品的SEM图；
图3为本发明实施例1转晶掺铝碳酸钴成品的XRD图；
图4为本发明实施例2转晶掺铝碳酸钴晶种的SEM图；
图5为本发明实施例2转晶掺铝碳酸钴成品的SEM图；
图6为本发明实施例3转晶掺铝碳酸钴成品的SEM图；
图7为本发明对比例1掺铝碳酸成品钴的SEM图；
图8为本发明对比例2掺铝碳酸钴晶种的SEM图；
图9为本发明对比例2掺铝碳酸钴成品的SEM图；
图10为本发明对比例3掺铝碳酸钴成品的SEM图；
图11为本发明对比例4掺铝碳酸钴成品的SEM图。
具体实施方式
下面结合具体实施例对本发明做进一步的说明。
实施例1：
一种转晶掺铝碳酸钴的制备方法，包括以下步骤：
(1)配制溶液：将氯化钴，氯化铝配制成混合金属溶液，并配制第一碳酸氢铵溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液，其中混合金属溶液中钴的浓度为2.0mol/L，铝钴元素的摩尔比为0.01，第一碳酸氢铵溶液的浓度为1.0mol/L，第二碳酸氢铵溶液的浓度为3mol/L，第三碳酸氢铵溶液的浓度为2mol/L；
(2)转晶碳酸钴晶种合成：向反应釜中加入第一碳酸氢铵溶液作为底液，体积占反应釜总体积的30％，底液pH值为8.3，开始升温至45℃，在高速搅拌的条件下并流加入混合金属溶液和第二碳酸氢铵溶液；其中混合金属溶液和第二碳酸氢铵溶液均为单条加液管同时进液，混合金属溶液流量为300L/h，第二碳酸氢铵溶液流量为150L/h，当pH值下降至7.50时通过PLC控制系统调节第二碳酸氢铵溶液的 流量以稳定pH值恒为7.50，当反应釜内液位到总体积的83％时开启浓缩，浓缩期间混合金属溶液和第二碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积83％，当晶种样品测得的BET为0.35cm2/g时完成转晶掺铝碳酸钴晶种合成，得到的转晶掺铝碳酸钴晶种的SEM图如图1所示，测得D50为8.6μm，同时根据图1可知，一次颗粒为块状，无铝偏析物；
(3)碳酸钴晶型转变及生长：将反应温度升至65℃，控制反应釜升温速度在20℃/h，混合金属溶液和第三碳酸氢铵溶液并流加入，并开启浓缩，其中混合金属溶液和第三碳酸氢铵溶液均为三条加液管同时进液，混合金属溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液用到的加液管的尺寸相同，其中混合金属溶液流量200L/h，第三碳酸氢铵溶液通过PLC控制系统调节，使晶种生长阶段pH值恒为8.0，当浓缩期间混合金属溶液和第三碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积83％，反应过程中母液中钴离子浓度在40mg/L，当粒度生长至16.7μm，得到转晶掺铝碳酸钴浆料；
(4)转晶掺铝碳酸钴洗涤、烘干、过筛：将反应釜内浆料达到离心机过滤，用85℃热纯水洗涤40min，取滤饼在110℃下干燥至水分含量0.1％后，过400目振动筛，包装后得到转晶掺铝碳酸钴成品，得到的转晶掺铝碳酸钴成品的SEM图如图2所示，得到的转晶掺铝碳酸钴成品的XRD图如图3所示，其中D50为16.7μm，铝元素含量为4820ppm，由图2可知，一次颗粒呈片状，无铝偏析物，由图3可知，得到的转晶掺铝碳酸钴成品为碳酸钴和碱式碳酸钴铝混合物。
实施例2：
一种转晶掺铝碳酸钴的制备方法，包括以下步骤：
(1)配制溶液：将硫酸钴，硫酸铝配制成混合金属溶液，并配制第一碳酸氢铵溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液，混合金属溶液中钴的浓度为2.2mol/L，铝钴元素的摩尔比为0.008，第一碳酸氢铵溶液的浓度为0.8mol/L，第二碳酸氢铵溶液浓度为2.8mol/L，第三碳酸氢铵溶液浓度为1.7mol/L；
(2)转晶碳酸钴晶种合成：向反应釜中加入第一碳酸氢铵溶液作为底液，体积占反应釜总体积的40％，底液pH值为7.5，开始升温至43℃，在高速搅拌的条件下并流加入混合金属溶液和第二碳酸氢铵溶液；其中混合金属溶液和第二碳酸氢铵溶液均为单条加液管同时进液，混合金属溶液流量为250L/h，第二碳酸氢铵溶液流量为120L/h，当pH值下降至7.40时通过PLC控制系统调节第二碳酸氢铵溶液的 流量以稳定pH值为7.40，当反应釜内液位到总体积的80％开启浓缩，浓缩期间混合金属溶液和碳酸氢铵A溶液持续通入并保持釜内液位稳定在总体积80％，当晶种样品测得的BET为0.41cm2/g时完成转晶掺铝碳酸钴晶种合成，得到的转晶掺铝碳酸钴晶种的SEM图如图4所示，测得D50为10.5μm，由图4可知，一次颗粒为块状，无铝偏析物；
(3)碳酸钴晶型转变及生长：将反应温度升至67℃，控制反应釜升温速度在24℃/h，混合金属溶液和第三碳酸氢铵溶液并流加入，并开启浓缩，其中混合金属溶液和第三碳酸氢铵溶液均为四条加液管同时进液，混合金属溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液用到的加液管的尺寸相同，其中混合金属溶液流量250L/h，第三碳酸氢铵溶液的流量通过PLC控制系统调节，使晶种生长阶段pH值恒为8.2，浓缩期间混合金属溶液和第三碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积80％，反应过程中母液中钴离子浓度在20mg/L，当粒度生长至18.8μm，得到转晶掺铝碳酸钴浆料；
(4)转晶掺铝碳酸钴洗涤、烘干、过筛：将反应釜内浆料达到离心机过滤，用90℃热纯水洗涤30min，取滤饼在120℃下干燥至水分含量0.28％后，过400目振动筛，包装后得到掺铝碳酸钴成品，得到的转晶掺铝碳酸钴成品的SEM图如图5所示，其中D50为18.8μm，铝元素含量为3693ppm，由图5可知，一次颗粒为片状，无铝偏析物。
实施例3：
一种转晶掺铝碳酸钴的制备方法，包括以下步骤：
(1)配制溶液：将硝酸钴，硝酸铝配制成混合金属溶液，并配制第一碳酸氢铵溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液，混合金属溶液中钴的浓度为1.5mol/L，铝钴元素的摩尔比为0.005，第一碳酸氢铵溶液的浓度为1.6mol/L，第二碳酸氢铵溶液浓度为2.5mol/L，第三碳酸氢铵溶液浓度为1.5mol/L；
(2)转晶碳酸钴晶种合成：向反应釜中加入第一碳酸氢铵溶液作为底液，体积占反应釜总体积的35％，底液pH值为8.5，开始升温至40℃，在高速搅拌的条件下并流加入混合金属溶液和第二碳酸氢铵溶液；其中混合金属溶液和第二碳酸氢铵溶液均为单条加液管同时进液，混合金属溶液流量为200L/h，第二碳酸氢铵溶液流量为100L/h，当pH值下降至7.60时通过PLC控制系统调节第二碳酸氢铵溶液的流量以稳定pH值恒为7.60，当反应釜内液位到总体积的85％开启浓缩，浓缩期间 混合金属溶液和第二碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积85％，当晶种样品测得的BET为0.56cm2/g时完成转晶掺铝碳酸钴晶种合成，测得D50为12.5μm，一次颗粒为块状，无铝偏析物；
(3)碳酸钴晶型转变及生长：将反应温度升至70℃，控制反应釜升温速度在30℃/h，混合金属溶液和第三碳酸氢铵溶液并流加入，并开启浓缩，其中混合金属溶液和第三碳酸氢铵溶液均为二条加液管同时进液，混合金属溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液用到的加液管的尺寸相同，其中混合金属溶液流量100L/h，第三碳酸氢铵溶液的流量通过PLC控制系统调节，使晶种生长阶段pH值恒为7.8，浓缩期间混合金属溶液和第三碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积85％，反应过程中母液中钴离子浓度在50mg/L，当粒度生长至17.5μm，得到转晶掺铝碳酸钴浆料；
(4)转晶掺铝碳酸钴洗涤、烘干、过筛：将反应釜内浆料达到离心机过滤，用95℃热纯水洗涤600min，取滤饼在110℃下干燥至水分含量0.82％后，过400目振动筛，包装后得到掺铝碳酸钴成品，得到的转晶掺铝碳酸钴成品的SEM图如图6所示，其中D50为17.5μm，铝元素含量为2420ppm，由图6可知，一次颗粒为片状，无铝偏析物。
对比例1：
一种掺铝碳酸钴的制备方法，包括以下步骤：
(1)与实施例1的步骤(1)相同；
(2)掺铝碳酸钴晶种合成：与实施例1的步骤(2)相同；
(3)掺铝碳酸钴生长：将反应温度控制在45℃不变，与晶种温度相同，混合金属溶液和第三碳酸氢铵溶液并流加入，并开启浓缩，其中混合金属溶液和第三碳酸氢铵溶液均为三条加液管同时进液，混合金属溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液用到的加液管的尺寸相同，其中混合金属溶液流量200L/h，第三碳酸氢铵溶液通过PLC控制系统调节，使晶种生长阶段pH值恒为7.50，与晶种反应控制的pH值相同，浓缩期间混合金属溶液和第三碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积83％，反应过程中母液中钴离子浓度在150mg/L，当粒度生长至16.6μm，得到掺铝碳酸钴浆料；
(4)掺铝碳酸钴洗涤、烘干、过筛：将反应釜内浆料达到离心机过滤，用85℃热纯水洗涤40min，取滤饼在110℃下干燥至水分含量0.21％后，过400目振动筛， 包装后得到掺铝碳酸钴成品，得到的掺铝碳酸钴成品的SEM图如图7所示，其中D50为16.6μm，铝元素含量为4758ppm，由图7可知，一次颗粒为块状，未发生转晶，且表面有铝片析出。
对比例2：
一种掺铝碳酸钴的制备方法，包括以下步骤：
(1)与实施例1的步骤(1)相同；
(2)掺铝碳酸钴晶种合成：向反应釜中加入第一碳酸氢铵溶液作为底液，体积占反应釜总体积的30％，底液pH值为8.3，开始升温至43℃，在高速搅拌的条件下并流加入混合金属溶液和第二碳酸氢铵溶液；其中混合金属溶液和第二碳酸氢铵溶液均为单条加液管同时进液，混合金属溶液流量为300L/h，第二碳酸氢铵溶液流量为150L/h，当pH值下降至7.50时通过PLC控制系统调节第二碳酸氢铵溶液的流量以稳定pH值恒为7.50，当反应釜内液位到总体积的83％时开启浓缩，浓缩期间混合金属溶液和第二碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积83％，当晶种样品测得的BET为5.2cm2/g时完成掺铝碳酸钴晶种合成，到的掺铝碳酸钴晶种的SEM图如图8所示，测得D50为6.2μm，由图8可知，一次颗粒为小块状，无明显铝偏析物；
(3)掺铝碳酸钴生长：与实施例1的步骤(3)相同；
(4)掺铝碳酸钴洗涤、烘干、过筛：将反应釜内浆料达到离心机过滤，用85℃热纯水洗涤40min，取滤饼在110℃下干燥至水分含量0.15％后，过400目振动筛，包装后得到掺铝碳酸钴成品，得到的掺铝碳酸钴成品的SEM图如图9所示，其中D50为16.5μm，铝元素含量为4810ppm，由图9可知，一次颗粒呈大块状，有明显的铝偏析物。
对比例3：
一种掺铝碳酸钴的制备方法，包括以下步骤：
(1)与实施例1的步骤(1)相同；
(2)与实施例1的步骤(2)相同；
(3)掺铝碳酸钴生长：将反应温度升高到50℃，控制升温速度5℃/h，混合金属溶液和第三碳酸氢铵溶液并流加入，并开启浓缩，其中混合金属溶液和第三碳酸氢铵溶液均为三条加液管同时进液，混合金属溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液用到的加液管的尺寸相同，其中混合金属溶液流量200L/h，第三碳酸氢铵 溶液通过PLC控制系统调节，使晶种生长阶段pH值恒为8.0，浓缩期间混合金属溶液和第三碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积83％，反应过程中母液中钴离子浓度在150mg/L，当粒度生长至16.7μm，得到掺铝碳酸钴浆料；
(4)掺铝碳酸钴洗涤、烘干、过筛：将反应釜内浆料达到离心机过滤，用85℃热纯水洗涤40min，取滤饼在120℃下干燥至水分含量0.28％后，过400目振动筛，包装后得到掺铝碳酸钴成品，得到的掺铝碳酸钴成品的SEM图如图10所示，其中D50为16.9μm，铝元素含量为4729ppm，由图10可知，一次颗粒为块状和片状的混合晶型，有明显的铝偏析扦插在颗粒表面。
对比例4：
一种掺铝碳酸钴的制备方法，包括以下步骤：
(1)配制溶液：将氯化钴，氯化铝配制成混合金属溶液，并配制第一碳酸氢铵溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液，混合金属溶液中钴的浓度为2.0mol/L，铝钴元素的摩尔比为0.01，第一碳酸氢铵溶液的浓度为1.0mol/L，第二碳酸氢铵溶液和第三碳酸氢铵溶液的浓度均为3mol/L；
(2)转晶碳酸钴晶种合成：向反应釜中加入第一碳酸氢铵溶液作为底液，体积占反应釜总体积的30％，底液pH值为8.3，开始升温至45℃，在高速搅拌的条件下并流加入混合金属溶液和第二碳酸氢铵溶液；其中混合金属溶液和第二碳酸氢铵溶液均为单条加液管同时进液，混合金属溶液流量为300L/h，第二碳酸氢铵溶液流量为150L/h，当pH值下降至7.50时通过PLC控制系统调节第二碳酸氢铵溶液的流量以稳定pH值恒为7.50，当反应釜内液位到总体积的83％时开启浓缩，浓缩期间混合金属溶液和第二碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积83％，当晶种样品测得的BET为0.30cm2/g时完成转晶掺铝碳酸钴晶种合成；
(3)碳酸钴晶型转变及生长：将反应温度升至65℃，控制反应釜升温速度在20℃/h，混合金属溶液和第三碳酸氢铵溶液并流加入，并开启浓缩，其中混合金属液和第三碳酸氢铵溶液为单条加液管同时进液，混合金属溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液用到的加液管的尺寸相同，其中混合金属溶液流量200L/h，第三碳酸氢铵溶液通过PLC控制系统调节，使晶种生长阶段pH值恒为8.0，浓缩期间混合金属溶液和第三碳酸氢铵溶液持续通入并保持釜内液位稳定在总体积83％，反应过程中母液中钴离子浓度在40mg/L，当粒度生长至16.7μm，得到掺铝碳酸钴浆料；
(4)转晶掺铝碳酸钴洗涤、烘干、过筛：将反应釜内浆料达到离心机过滤，用85℃热纯水洗涤40min，取滤饼在110℃下干燥至水分含量0.5％后，过400目振动筛，包装后得到转晶掺铝碳酸钴成品，得到的掺铝碳酸钴成品的SEM图如图11所示，其中D50为16.7μm，铝元素含量为4810ppm，由图11可知，一次颗粒为块状，未发生转晶，有铝偏析扦插在颗粒表面。
通过对比实施例1和对比例1可以得出，转晶后的形成的片状形貌的碱式碳酸钴铝既保证了合成过程的铝分布的均匀性，且由于其结构稳定性，又避免了铝片在成品后处理过程中析出；通过对比实施例1和对比例2可以得出，较大比表面积的晶种在高温和高pH的生长条件下不能发生转晶，一次颗粒依然继承晶种的块状形貌，且随着颗粒生长变的粗大；通过对比实施例1和对比例3可以得出，在碳酸钴晶型转变及生长阶段，较慢的升温速率和较低的温度，颗粒未能转晶完全，一次颗粒为粗块状和片状附着，颗粒表面一致性差；通过对比实施例1和对比例4可以得出，在掺铝碳酸钴晶型转变及生长阶段采用和晶种制备阶段相同的碳酸氢铵浓度和单条加液管加液的方式仍然会保持母液中碳酸根离子浓度处在较高值，颗粒转晶不能发生。
将上述实施例1-3和对比例1-4制备得到的碳酸钴前驱体在箱式炉内700℃煅烧4h，然后按照相同条件制备成电池进行电化学测试，大致方法为：将前驱体与碳酸锂按照一定比例混合烧结制备成的钴酸锂材料作为正极，石墨作为负极，六氟磷酸锂为电解液制成纽扣电池，电化学测试电压为4.55V，进行1C高温循环测试，温度为45℃，测试结果见下表1：
表1：电池循环性能测试：
从表1中数据可以看出，各实施例中制备的转晶后的掺铝前驱体在制备成钴酸 锂后更有利于锂的嵌入，有着优异的循环性能，其50周循环保持率能达到90.6％以上，80周循环保持率能达到81.5％以上，而对比例所制备的未转晶的掺铝前驱体由于其铝分布的不均匀，导致钴酸锂材料的高温循环性能较差。
上述实施例为本发明较佳的实施方式，但本发明的实施方式并不受上述实施例的限制，其他的任何未背离本发明的精神实质与原理下所作的改变、修饰、替代、组合、简化，均应为等效的置换方式，都包含在本发明的保护范围之内。

Claims (10)

  1. 一种转晶掺铝碳酸钴的制备方法，其特征在于：包括以下步骤：
    (1)将钴盐、铝盐配制成混合金属溶液，并配制第一碳酸氢铵溶液、第二碳酸氢铵溶液和第三碳酸氢铵溶液，其中所述第一碳酸氢铵溶液的浓度为0.8-1.6mol/L，所述第二碳酸氢铵溶液的浓度为2.5-3.0mol/L，所述第三碳酸氢铵溶液的浓度为1.5-2.0mol/L；
    (2)将所述混合金属溶液与所述第二碳酸氢铵溶液并流加入到所述第一碳酸氢铵溶液中混合进行反应，并控制反应温度为40-45℃，直至生成比表面积为0.3-0.6cm2/g的转晶掺铝碳酸钴晶种；
    (3)向步骤(2)得到的含所述转晶掺铝碳酸钴晶种的溶液中并流加入所述混合金属溶液与所述第三碳酸氢铵溶液混合进行反应，直至所述转晶掺铝碳酸钴晶种的粒度生长至16.0-19.0μm，固液分离，并对得到的固体物进行洗涤、烘干，得到所述转晶掺铝碳酸钴。
  2. 根据权利要求1所述的转晶掺铝碳酸钴的制备方法，其特征在于：步骤(1)中，所述混合金属溶液中，钴离子的浓度为1.5-2.5mol/L，铝元素与钴元素的摩尔比为0.001-0.01。
  3. 根据权利要求2所述的转晶掺铝碳酸钴的制备方法，其特征在于：步骤(2)和步骤(3)的反应是在反应釜中进行，步骤(2)中，先将所述第一碳酸氢铵溶液作为底液加入到所述反应釜中并升温，在搅拌状态下通过加液管并流加入所述混合金属溶液与所述第二碳酸氢铵溶液进行反应，当所述反应釜中的液位达到设定值时开启浓缩，监控生成的晶种的比表面积，直至所述晶种的比表面积达到目标值。
  4. 根据权利要求3所述的一种转晶掺铝碳酸钴的制备方法，其特征在于：步骤(2)中，所述底液占所述反应釜总体积的20％-30％，所述混合金属溶液流量为200-300L/h，所述第二碳酸氢铵溶液的流量为100-150L/h，当所述反应釜中的液位达到所述反应釜总体积的80％-85％时开启浓缩，并持续通入所述混合金属溶液与所述第二碳酸氢铵溶液使釜内液位稳定在总体积80％-85％。
  5. 根据权利要求3所述的转晶掺铝碳酸钴的制备方法，其特征在于：步骤(2)中控制反应的pH为7.0-8.5。
  6. 根据权利要求3所述的转晶掺铝碳酸钴的制备方法，其特征在于：步骤(3)中，在 开启浓缩的前提下通过加液管并流加入所述混合金属溶液与所述第三碳酸氢铵溶液，所述混合金属溶液的流量为100-200L/h，通过持续加入所述第三碳酸氢铵溶液控制反应的pH为7.8-8.2，并使釜内液位稳定在总体积80％-85％，所述混合金属溶液、所述第二碳酸氢铵溶液和所述第三碳酸氢铵溶液用到的所述加液管的尺寸相同。
  7. 根据权利要求3所述的转晶掺铝碳酸钴的制备方法，其特征在于：步骤(3)中，以10-30℃/h的升温速度将反应温度升至60-80℃。
  8. 根据权利要求3所述的转晶掺铝碳酸钴的制备方法，其特征在于：步骤(3)中所述混合金属溶液的加液管数量多于步骤(2)中所述混合金属溶液的加液管数量，步骤(3)中所述第三碳酸氢铵溶液的加液管数量多于步骤(2)中所述第二碳酸氢铵溶液的加液管数量。
  9. 根据权利要求8所述的转晶掺铝碳酸钴的制备方法，其特征在于：步骤(2)中所述混合金属溶液和所述第二碳酸氢铵溶液的加液管数量均为一条。
  10. 权利要求1-9任一项所述的制备方法制备的转晶掺铝碳酸钴在制备钴酸锂正极材料中的应用。
PCT/CN2023/078766 2022-08-22 2023-02-28 一种转晶掺铝碳酸钴的制备方法和应用 Ceased WO2024040901A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202211005331.5 2022-08-22
CN202211005331.5A CN115321605B (zh) 2022-08-22 2022-08-22 一种转晶掺铝碳酸钴的制备方法和应用

Publications (1)

Publication Number Publication Date
WO2024040901A1 true WO2024040901A1 (zh) 2024-02-29

Family

ID=83926143

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/078766 Ceased WO2024040901A1 (zh) 2022-08-22 2023-02-28 一种转晶掺铝碳酸钴的制备方法和应用

Country Status (3)

Country Link
CN (1) CN115321605B (zh)
FR (1) FR3138913A1 (zh)
WO (1) WO2024040901A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115321605B (zh) * 2022-08-22 2023-10-17 广东邦普循环科技有限公司 一种转晶掺铝碳酸钴的制备方法和应用

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007095571A (ja) * 2005-09-29 2007-04-12 Seimi Chem Co Ltd リチウム含有複合酸化物の製造方法
US20070264573A1 (en) * 2005-09-28 2007-11-15 Agc Seimi Chemical Co., Ltd. Process for producing lithium-containing composite oxide
CN111646519A (zh) * 2020-07-17 2020-09-11 衢州华友钴新材料有限公司 一种掺铝四氧化三钴的制备方法
CN113636604A (zh) * 2021-08-30 2021-11-12 衢州华友钴新材料有限公司 一种高掺铝小粒径碳酸钴颗粒的制备方法
CN113816435A (zh) * 2021-08-27 2021-12-21 广东邦普循环科技有限公司 一种转晶前驱体及其制备方法
CN113830839A (zh) * 2021-08-18 2021-12-24 广东邦普循环科技有限公司 片状形貌掺铝碳酸钴的制备方法及其应用
CN115321605A (zh) * 2022-08-22 2022-11-11 广东邦普循环科技有限公司 一种转晶掺铝碳酸钴的制备方法和应用

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113307308B (zh) * 2021-06-25 2023-05-23 巴斯夫杉杉电池材料有限公司 一种掺杂型大颗粒碳酸钴及其制备方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070264573A1 (en) * 2005-09-28 2007-11-15 Agc Seimi Chemical Co., Ltd. Process for producing lithium-containing composite oxide
JP2007095571A (ja) * 2005-09-29 2007-04-12 Seimi Chem Co Ltd リチウム含有複合酸化物の製造方法
CN111646519A (zh) * 2020-07-17 2020-09-11 衢州华友钴新材料有限公司 一种掺铝四氧化三钴的制备方法
CN113830839A (zh) * 2021-08-18 2021-12-24 广东邦普循环科技有限公司 片状形貌掺铝碳酸钴的制备方法及其应用
CN113816435A (zh) * 2021-08-27 2021-12-21 广东邦普循环科技有限公司 一种转晶前驱体及其制备方法
CN113636604A (zh) * 2021-08-30 2021-11-12 衢州华友钴新材料有限公司 一种高掺铝小粒径碳酸钴颗粒的制备方法
CN115321605A (zh) * 2022-08-22 2022-11-11 广东邦普循环科技有限公司 一种转晶掺铝碳酸钴的制备方法和应用

Also Published As

Publication number Publication date
CN115321605B (zh) 2023-10-17
CN115321605A (zh) 2022-11-11
FR3138913A1 (fr) 2024-02-23

Similar Documents

Publication Publication Date Title
KR102654565B1 (ko) Ncma 하이 니켈 4차 전구체의 습식 합성 방법
CN110357057B (zh) 一种片状磷酸铁及其制备方法与应用
CN113562711B (zh) 磷酸铁及其制备方法和应用
CN116253304B (zh) 高振实密度磷酸铁及其制备方法、磷酸铁锂
CN113830839B (zh) 片状形貌掺铝碳酸钴的制备方法及其应用
CN113247971B (zh) 一种碳酸盐前驱体及其制备方法
CN108011101A (zh) 一种大粒径均匀掺铝四氧化三钴的制备方法
GB2620523A (en) Recovery method for lithium iron phosphate waste and application
CN107640792A (zh) 一种高密实小粒径镍钴锰氢氧化物及其制备方法
CN108910932B (zh) 一种碳酸钠沉淀制备窄分布超细氧化钇的方法
WO2023207281A1 (zh) 镁钛共掺杂碳酸钴的制备方法及其应用
CN115535985A (zh) 一种氧化沉淀一体工艺合成电池级磷酸铁方法
CN109962234A (zh) 浓度梯度的单晶正极材料及其制备方法
WO2023024584A1 (zh) 掺镍碳酸钴及其制备方法和应用
CN111422915A (zh) 一种低硫致密晶型碳酸钴的制备方法
CN115504516A (zh) 一种铝镍共掺碳酸钴前驱体及其制备方法与应用
CN115295748A (zh) 一种利用多金属mof前驱体制备锂离子电池单晶三元正极材料的方法及其产品
CN113363438A (zh) 一种含有La、Ce共掺杂的NCMA四元前驱体制备方法
CN115321605B (zh) 一种转晶掺铝碳酸钴的制备方法和应用
WO2025260452A1 (zh) 片状高铁磷比磷酸铁及其制备方法、正极材料和正极极片
WO2023197483A1 (zh) 一种纳米磷酸铁锰锂的水热合成方法
CN105060266B (zh) 一种纳米磷酸铁锂的水热合成方法
CN116177511B (zh) 一种磷酸铁次品重造的方法
CN110867577A (zh) 一种三维纳米线阵列结构的811ncm三元正极材料及其制备方法
CN119873909A (zh) 一种高性能单晶多孔大核心ncm高镍三元前驱体的制备方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23855998

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 23855998

Country of ref document: EP

Kind code of ref document: A1