CN104986807A - Spherical tricobalt tetraoxide preparation method - Google Patents

Abstract

The present invention provides a spherical tricobalt tetraoxide preparation method, wherein a separately prepared cobalt salt solution, a mixing solution of a complexing agent and a hydroxide, and an oxidizing agent solution are simultaneously introduced into a reaction container through a cocurrent flow method, stirring is performed to carry out a reaction, and after completing the reaction, filtration, slurrying washing, drying, baking and calcining are performed to obtain the spherical tricobalt tetraoxide product. The method has the following advantages that the mixture of CoOOH and Co3O4 is obtained through oxidation from the solution at the low temperature, and the spherical tricobalt tetraoxide powder with characteristics of high bulk density, high tap density and good one-time crystal nucleus forming can be prepared through the calcination.

Description

A kind of preparation method of spherical cobaltic-cobaltous oxide

Technical field

The invention belongs to anode material for lithium-ion batteries technical field, be specifically related to a kind of preparation method of precursor of lithium ionic cell positive material-spherical cobaltic-cobaltous oxide.

Background technology

Co ₃o ₄being a kind of functional materials with special construction and performance, is the presoma of main flow lithium ion cell anode material lithium cobaltate.Prepare the Co of lithium ion battery positive electrode material ₃o ₄physicals comprise tap density, size distribution, specific surface area, crystal morphology, foreign matter content, chemical property, thermal stabilities etc. have very strict requirement.Existing process for producing cobaltic-cobaltous oxide is mainly by divalent cobalt solution solvable carbonate or oxalate precipitation, and then calcined by throw out obtained under the high temperature of 200 ~ 900 DEG C, this method not only energy consumption is high, and the Co of preparation ₃o ₄short texture, density is low, product particle skewness, and consistence is poor, can not meet battery industry to cell-grade Co ₃o ₄requirement.

Patent CN 200910099751.2, disclose " preparation method of spherical cobaltosic oxide with high battery security ", specifically by the cobalt salt solution prepared and containing quantitative complexing agent hydroxide solution and stream adds in reactive tank, pass into oxidant reaction, ageing is carried out after reaction, press filtration is washed, and except magnetic foreign body, obtains spherical Co ₃o ₄.But Co prepared by this method ₃o ₄its D ₅₀=4 ~ 6 μm, scope is narrower.Patent CN201310096506.2 discloses " a kind of method of hybrid oxidative synthesis spherical cobaltic-cobaltous oxide ", the mixed aqueous solution of rose vitriol and complexing agent, aqueous sodium hydroxide solution are injected in reactor continuously through delicate flow Controlling System, adopt the electrochemical method adding oxygenant, oxygen and input dc power that reaction mass is generated hydroxy cobalt oxide sphaerocrystal during reaction, flow out continuously through reactor overflow port again, through ageing, washing, hot-air seasoning dehydration, obtain spherical Co ₃o ₄but this invention reaction process is more loaded down with trivial details.

Summary of the invention

The invention provides a kind of preparation method of spherical cobaltic-cobaltous oxide, Co prepared by the method ₃o ₄loose density and tap density high, nucleation is good.

The present invention is achieved by the following technical solutions:

A preparation method for spherical cobaltic-cobaltous oxide, is characterized in that comprising the following steps:

A, preparation cobalt salt solution:

Compound concentration is the cobalt salt solution of 60 ~ 150g/L, and described cobalt salt is selected from least one in cobalt chloride, Jing Ti/Bao Pian COBALT NITRATE CRYSTALS/FLAKES, rose vitriol;

The mixed solution of b, preparation complexing agent and oxyhydroxide:

Compound concentration is 80 ~ 150g/L hydroxide solution, and described oxyhydroxide is selected from least one in sodium hydroxide, potassium hydroxide; Configuration concentration is the enveloping agent solution of 80 ~ 200g/L, and described complexing agent is selected from the one in ammoniacal liquor, quadrol, disodium ethylene diamine tetraacetate, citric acid; By the hydroxide solution of preparation and the mixing of described enveloping agent solution, obtain the mixed solution of complexing agent and oxyhydroxide, the volume ratio of described enveloping agent solution and hydroxide solution is 2 ~ 9:100;

C, preparation oxidizing agent solution:

Compound concentration is the oxidizing agent solution of 15 ~ 50g/L; Described oxygenant is hydrogen peroxide;

D, building-up reactions:

To adopt and the mixed solution of described cobalt salt solution, complexing agent and oxyhydroxide and oxidizing agent solution pass in reactor by the method flowed, stirring reaction; Controlling temperature of reaction is 30 ~ 100 DEG C; Controlling cobalt salt solution flow is 10 ~ 40L/h, and oxidizing agent solution flow is 6 ~ 15L/h; Be 7 ~ 14 by the pH value of the flow control reaction system of the mixed solution of complexing agent and oxyhydroxide;

E, filtration, pulp, washing and drying:

By reacting liquid filtering after reaction terminates, dry dry after filter cake pulp, washing;

F, calcining

Calcined by dried material, calcining temperature is 300-700 DEG C, obtains spherical cobaltic-cobaltous oxide.

In reaction of the present invention, Co ²⁺first generate Co (OH) with the mixture reaction of complexing agent and oxyhydroxide ₂, then Co (OH) ₂be oxidized to Co ₃o ₄and CoOOH.Co in CoOOH is trivalent, and this is conducive to synthesizing lithium cobaltate cathode material, because the cobalt in cobalt acid lithium is also trivalent.

The method in the solution direct oxidation obtains CoOOH and Co ₃o ₄mixture, by this mixture 300-700 DEG C of calcining, obtain high apparent density, high tap density, the spherical cobaltic-cobaltous oxide of low specific surface area.

The spherical cobaltic-cobaltous oxide density of method synthesis of the present invention is high, even particle size distribution, is easy to realize suitability for industrialized production, can provides a kind of desirable cell positive material presoma.The cobaltosic oxide particle size distribution solving conventional solid-state method production is wide, the shortcomings such as sintering activity is poor, unstable quality, and energy expenditure is large.

Accompanying drawing explanation

Spherical cobaltic-cobaltous oxide product scanning electron microscope image prepared by Fig. 1 embodiment 1;

Spherical cobaltic-cobaltous oxide product scanning electron microscope image prepared by Fig. 2 embodiment 2;

Spherical cobaltic-cobaltous oxide product scanning electron microscope image prepared by Fig. 3 embodiment 3.

Embodiment

Be described principle of the present invention and feature below, illustrated embodiment, only for explaining the present invention, is not intended to limit scope of the present invention.

Embodiment 1

A, preparation cobalt salt solution: compound concentration is the cobalt chloride solution of 80g/L;

The mixed solution of b, preparation complexing agent and oxyhydroxide: the ammonia soln adding 180g/L in the sodium hydroxide solution of 100g/L, the ratio of ammonia soln and sodium hydroxide solution is 5::100; C, preparation oxidizing agent solution:

The hydrogen peroxide solution of preparation 20g/L;

D, building-up reactions:

To adopt and the mixed solution of cobalt chloride solution, complexing agent and oxyhydroxide and hydrogen peroxide solution pass in reactor by the method flowed, stirring reaction; Controlling temperature of reaction is 70 DEG C; Controlling cobalt chloride solution flow is 18L/h, and hydrogen peroxide solution flow is 7.5L/h; Be 9 by the pH value of the flow control reaction system of the mixed solution of complexing agent and oxyhydroxide;

E, filtration, pulp, washing and drying:

By reacting liquid filtering after reaction terminates, by the pure water pulping and washing of filter cake with more than 90 DEG C, dry oven dry;

F, calcining

Calcined by dried material, 500 DEG C of calcining 8h, obtain spherical cobaltic-cobaltous oxide, indices is in table 1, and scanning electron microscope image is shown in Fig. 1.

Spherical cobaltic-cobaltous oxide product constituent content (g/t) figure prepared by table 1 embodiment 1

Embodiment 2

A, preparation cobalt salt solution: compound concentration is the cobalt nitrate aqueous solution of 120g/L;

The mixed solution of b, preparation complexing agent and oxyhydroxide: the disodium ethylene diamine tetra-acetic acid solution adding 80g/L in the sodium hydroxide solution of 90g/L, and the ratio of disodium ethylene diamine tetra-acetic acid solution and sodium hydroxide solution is 5:100;

C, preparation oxidizing agent solution:

Compound concentration is the hydrogen peroxide solution of 30g/L;

D, building-up reactions:

To adopt and the mixed solution of cobalt chloride solution, complexing agent and oxyhydroxide and hydrogen peroxide solution pass in reactor by the method flowed, stirring reaction; Controlling temperature of reaction is 65 DEG C; Controlling cobalt nitrate aqueous solution flow is 20L/h, and hydrogen peroxide solution flow is 9L/h; Be 10 by the pH value of the flow control reaction system of the mixed solution of complexing agent and oxyhydroxide;

E, filtration, pulp, washing and drying:

With embodiment 1.

F, calcining

Calcined by dried material, 600 DEG C of calcining 5h, obtain spherical cobaltic-cobaltous oxide, the product D of preparation ₅₀be 6.69 μm, loose density is 1.66g/cm ³, tap density is 2.8g/cm ³, specific surface area is 0.6m ²/ g, magnetic foreign body content 0.442g/t, cobalt contents is 72.94%, and constituent content is in table 2, and scanning electron microscope image is shown in Fig. 2.

Spherical cobaltic-cobaltous oxide product constituent content prepared by table 2 embodiment 2

Embodiment 3

A, preparation cobalt salt solution: compound concentration is the cobalt nitrate aqueous solution of 110g/L;

The mixed solution of b, preparation complexing agent and oxyhydroxide: add the ammonia soln that massfraction is 120g/L in the sodium hydroxide solution of 120g/L, and the volume ratio of ammonia soln and sodium hydroxide solution is 7:100;

C, preparation oxidizing agent solution:

Compound concentration is the hydrogen peroxide solution of 25g/L.

D, building-up reactions:

To adopt and the mixed solution of cobalt chloride solution, complexing agent and oxyhydroxide and hydrogen peroxide solution pass in reactor by the method flowed, stirring reaction; Controlling temperature of reaction is 70 DEG C; Controlling cobalt nitrate aqueous solution flow is 30L/h, and hydrogen peroxide solution flow is 14L/h; Be 8.8 by the pH value of the flow control reaction system of the mixed solution of complexing agent and oxyhydroxide;

E, filtration, pulp, washing and drying:

With embodiment 1.

F, calcining

Calcined by dried material, 550 DEG C of calcining 6h, obtain spherical cobaltic-cobaltous oxide, the product D of preparation ₅₀be 7.364 μm, loose density is 1.41g/cm ³, tap density is 2.4g/cm ³, specific surface area is 2.83m ²/ g, magnetic foreign body content 0.298g/t, cobalt contents is the spherical cobaltic-cobaltous oxide of 72.9%, and constituent content is in table 3, and scanning electron microscope image is shown in Fig. 3.

Spherical cobaltic-cobaltous oxide product constituent content prepared by table 3 embodiment 3

Claims (2)

1. a preparation method for spherical cobaltic-cobaltous oxide, is characterized in that comprising the following steps:

A, preparation cobalt salt solution:

Compound concentration is the cobalt salt solution of 60 ~ 150g/L, and described cobalt salt is selected from least one in cobalt chloride, Jing Ti/Bao Pian COBALT NITRATE CRYSTALS/FLAKES, rose vitriol;

The mixed solution of b, preparation complexing agent and oxyhydroxide:

Compound concentration is 80 ~ 150g/L hydroxide solution, and described oxyhydroxide is selected from least one in sodium hydroxide, potassium hydroxide; Configuration concentration is the enveloping agent solution of 80 ~ 200g/L, and described complexing agent is selected from the one in ammoniacal liquor, quadrol, disodium ethylene diamine tetraacetate, citric acid; To prepare described hydroxide solution and the mixing of described enveloping agent solution, obtain the mixed solution of complexing agent and oxyhydroxide, the volume ratio of described enveloping agent solution and hydroxide solution is 2 ~ 9:100;

C, preparation oxidizing agent solution:

Compound concentration is the oxidizing agent solution of 15 ~ 50g/L;

D, building-up reactions:

To adopt and the mixed solution of described cobalt salt solution, complexing agent and oxyhydroxide and oxidizing agent solution pass in reactor by the method flowed, stirring reaction; Controlling temperature of reaction is 30 ~ 100 DEG C; Controlling cobalt salt solution flow is 10 ~ 40L/h, and oxidizing agent solution flow is 6 ~ 15L/h; Be 7 ~ 14 by the pH value of the flow control reaction system of the mixed solution of complexing agent and oxyhydroxide;

E, filtration, pulp, washing and drying:

By reacting liquid filtering after reaction terminates, dry dry after filter cake pulp, washing;

F, calcining

Calcined by dried material, calcining temperature is 300-700 DEG C, obtains spherical cobaltic-cobaltous oxide.

2. the preparation method of a kind of spherical cobaltic-cobaltous oxide as claimed in claim 1, is characterized in that: described oxygenant is the mixture of a kind of in sodium chlorate, clorox, Sodium Persulfate, hydrogen peroxide or at least two kinds.