CN110282964A - Sagger for sintering mullite-cordierite lithium battery cathode material and preparation method thereof - Google Patents

Abstract

The invention relates to a mullite-cordierite lithium battery anode material sintering sagger and a preparation method thereof. Its technical scheme is: 30-35wt% mullite particles, 20-25wt% mullite fine powder, 30-35wt% cordierite particles, 4-7wt% dextrin and 5-7wt% Guangxi white The mud is mixed and stirred to obtain a mixture A; then 30-35wt% mullite fine powder, 30-35wt% magnesium-aluminum spinel fine powder and 35-36wt% andalusite fine powder are stirred, dried, Grind to obtain mixture B. Then put the mixture A in the mould, sprinkle the layer of mixture B evenly on the surface of the pressure head, machine press it with the mouth of the bowl facing down, dry it, and keep it warm at 1300-1400°C for 5-6 hours to obtain Mo Sagger for sintering the anode material of Lithium-cordierite lithium battery. The invention has the advantages of low cost, simple process and high yield; the prepared mullite-cordierite lithium battery cathode material sagger has a large volume density, high compressive strength, excellent thermal shock resistance and good corrosion resistance.

Description

Sagger for sintering mullite-cordierite lithium battery cathode material and preparation method thereof

technical field

The invention belongs to the technical field of saggers for sintering positive electrode materials of lithium batteries. In particular, it relates to a mullite-cordierite lithium battery cathode material sintering sagger and a preparation method thereof.

Background technique

As a necessary carrier for the sintering of lithium battery positive electrode materials, sagger has the advantages of good thermal shock resistance, high strength, and good corrosion resistance of lithium battery positive electrode materials. Development is of great significance. In addition, saggers are difficult to recycle at this stage, resulting in a serious waste of resources. Research on long-term use of saggers is of great significance to resource conservation.

"A kind of mullite foam ceramics and its preparation method" (CN104311117A) patent technology, using sugar, aluminum and silicon fine powder as raw materials, using foaming technology to fire at high temperature, although it has low cost and high additional value, but due to the single phase formed in the material, its thermal shock performance is low.

"A kind of cordierite honeycomb ceramics and its preparation method" (CN101045629A) patented technology, using LiO ₂ , talc, calcined kaolin, alumina, aluminum hydroxide and silicon micropowder as raw materials, after mixing, smelting, extruding, wet The finished products are obtained by billet cutting, drying, dry billet cutting, and firing. Although they have high strength, the cost of raw materials is too high and it is difficult to apply them on a large scale.

"A lightweight cordierite-mullite composite ceramic material and its preparation method" (CN103922713A) patent technology, diaspore, amorphous silica, talcum powder and clay as raw materials, after stirring, molding and drying Fired at high temperature, although the strength and thermal shock resistance are good, but because cordierite is easy to react with the positive electrode material of lithium battery, the corrosion resistance of the material is weak and the service life is low.

Contents of the invention

The present invention aims to overcome the defects of the prior art, and aims to provide a method for preparing a mullite-cordierite lithium battery cathode material sintering sagger with low cost and simple process, and the mullite-cordierite prepared by the method The sagger used for sintering the positive electrode material of the bluestone lithium battery has good thermal shock resistance, excellent corrosion resistance and long service life.

For achieving the above object, the steps of the technical solution adopted in the present invention are:

Step 1, mix 30-35wt% mullite particles, 20-25wt% mullite fine powder, 30-35wt% cordierite particles, 4-7wt% dextrin and 5-7wt% Guangxi white mud Place in a mixer and stir for 1-1.2 hours to obtain Mixture A.

Step 2. Put 30-35wt% mullite fine powder, 30-35wt% magnesium-aluminum spinel fine powder and 35-36wt% andalusite fine powder in a mixer, stir for 1-1.2h, Dry at 100-110°C for 1-2 hours, grind until the particle size is ≤0.048mm, and obtain the mixture B.

Step 3: Put the mixture A in the mold first, then evenly sprinkle a layer of mixture B on the surface of the pressure head, and machine press it under the condition of 120-160 MPa with the mouth of the bowl facing down, and then press it at 100-100 MPa. drying at 110°C for 20 to 24 hours, and holding at 1300 to 1400°C for 5 to 6 hours to prepare a sagger for sintering the mullite-cordierite lithium battery cathode material.

The chemical composition of the mullite particles is: Al ₂ O ₃ ≥ 67.3wt%, SiO ₂ ≥ 30.4wt%, Fe ₂ O ₃ ≥ 0.92wt%; the density of the mullite particles is 2.82-2.97g/ cm ³ , the particle size of mullite particles is ≤3mm.

The mullite fine powder includes the mullite fine powder described in step 1 and the mullite fine powder described in step 2. The chemical composition of the mullite fine powder is: Al ₂ O ₃ ≥ 67.3 wt%, SiO ₂ ≥ 30.4 wt%, Fe ₂ O ₃ ≥ 0.92 wt%; the density of the mullite fine powder is 2.82-2.97 g/cm ³ , the particle size of mullite fine powder is ≤0.088mm.

The chemical composition of the cordierite particles is: Al ₂ O ₃ ≥ 34.1wt%, SiO ₂ ≥ 42.2wt%, MgO ≥ 14.3wt%; the density of the cordierite particles is 2.67-2.79g/cm ³ , cordierite The particle size of the particles is ≤3mm.

The particle size of the dextrin is ≤0.088mm.

The chemical composition of the Guangxi white mud is: Al ₂ O ₃ ≥ 35.2 wt%, SiO ₂ content ≥ 48.1 wt%, K ₂ O ≥ 2.1 wt%; the particle size of the Guangxi white mud is ≤ 0.088mm.

The chemical composition of the magnesium aluminum spinel fine powder: MgO content≥46.3wt%, _{Al2O3 content≥46.2wt} %; the particle size of the magnesium aluminum spinel fine powder≤0.088mm.

The chemical composition of the andalusite fine powder is: Al ₂ O ₃ ≥ 61.8 wt%, SiO ₂ ≥ 29.7; the particle size of the andalusite fine powder ≤ 0.088mm.

Owing to adopting above-mentioned technical scheme, the present invention has following advantage compared with prior art:

1. In the present invention, the prepared mixture A is placed in a mould, and a layer of the prepared mixture B is sprinkled on the surface of the pressure head, and the mouth of the bowl is machine pressed into shape, and dried and fired to obtain mullite - The sagger for cordierite lithium battery positive electrode material sintering (hereinafter referred to as "sagger"), so the process is simple; during the firing process, a dense protective layer is formed on the inner surface of the sagger, which increases the corrosion resistance of the sagger, Increased the service life of the sagger.

2. In the present invention, cordierite particles are used as the aggregate, and the crystal structure of the cordierite particles has good thermal shock resistance, so the prepared sagger has excellent thermal shock resistance.

3. The raw materials of the present invention are rich in sources and low in cost. There is no special equipment requirement in the process of preparing the sagger, and the preparation and firing time is short, so the cost is low and industrial production is easy.

The mullite-cordierite lithium battery anode material sintering sagger prepared by the present invention is tested: the yield is 99.6-99.9%; the apparent porosity is 8.4-10.4 g·cm ³ ; the bulk density is 2.86-3.26 g ·cm ³ ; the flexural strength is 10.2-13.2MPa; the compressive strength is 42.42-48.47MPa; the erosion index of the slag-resistant test by the static crucible method at 900°C is 2.2-3.7%.

Therefore, the present invention has the characteristics of low cost, simple process and high yield; the prepared mullite-cordierite lithium battery positive electrode material sintering sagger has a large volume density, high compressive strength, excellent thermal shock resistance and Good corrosion resistance.

Detailed ways

The present invention will be further described below in combination with specific embodiments, which are not intended to limit the scope of protection thereof.

In order to avoid duplication, the materials involved in this specific embodiment are first described in a unified manner as follows, and will not be repeated in the embodiments:

The chemical composition of the mullite particles is: Al ₂ O ₃ ≥ 67.3wt%, SiO ₂ ≥ 30.4wt%, Fe ₂ O ₃ ≥ 0.92wt%; the density of the mullite particles is 2.82-2.97g/ cm ³ , the particle size of mullite particles is ≤3mm.

The mullite fine powder includes the mullite fine powder described in step 1 and the mullite fine powder described in step 2. The chemical composition of the mullite fine powder is: Al ₂ O ₃ ≥ 67.3 wt%, SiO ₂ ≥ 30.4 wt%, Fe ₂ O ₃ ≥ 0.92 wt%; the density of the mullite fine powder is 2.82-2.97 g/cm ³ , the particle size of mullite fine powder is ≤0.088mm.

The chemical composition of the cordierite particles is: Al ₂ O ₃ ≥ 34.1wt%, SiO ₂ ≥ 42.2wt%, MgO ≥ 14.3wt%; the density of the cordierite particles is 2.67-2.79g/cm ³ , cordierite The particle size of the particles is ≤3mm.

The particle size of the dextrin is ≤0.088mm.

The chemical composition of the Guangxi white mud is: Al ₂ O ₃ ≥ 35.2 wt%, SiO ₂ content ≥ 48.1 wt%, K ₂ O ≥ 2.1 wt%; the particle size of the Guangxi white mud is ≤ 0.088mm.

The chemical composition of the magnesium aluminum spinel fine powder: MgO content≥46.3wt%, _{Al2O3 content≥46.2wt} %; the particle size of the magnesium aluminum spinel fine powder≤0.088mm.

The chemical composition of the andalusite fine powder is: Al ₂ O ₃ ≥ 61.8 wt%, SiO ₂ ≥ 29.7; the particle size of the andalusite fine powder ≤ 0.088mm.

Implementation 1

A mullite-cordierite lithium battery cathode material sintering sagger and a preparation method thereof. The preparation method described in this embodiment is:

Step 1. Mix 30-32wt% mullite particles, 20-22wt% mullite fine powder, 33-35wt% cordierite particles, 4-7wt% dextrin and 5-7wt% Guangxi white mud Place in a mixer and stir for 1-1.2 hours to obtain Mixture A.

Step 2. Put 30-32wt% mullite fine powder, 33-35wt% magnesium-aluminum spinel fine powder and 35-36wt% andalusite fine powder in a mixer, stir for 1-1.2h, Dry at 100-110°C for 1-2 hours, grind until the particle size is ≤0.048mm, and obtain the mixture B.

Step 3: Put the mixture A in the mold first, then evenly sprinkle a layer of mixture B on the surface of the pressure head, and machine press it under the condition of 120-130MPa with the mouth of the bowl facing down, and then press it under the condition of 100-100MPa. Dry at 110°C for 20 to 24 hours, and heat at 1300 to 1325°C for 5 to 6 hours to prepare a sagger for sintering the mullite-cordierite lithium battery cathode material.

Implementation 2

A mullite-cordierite lithium battery cathode material sintering sagger and a preparation method thereof. The preparation method described in this embodiment is:

Step 1. Mix 31-33wt% mullite particles, 21-23wt% mullite fine powder, 32-34t% cordierite particles, 4-7wt% dextrin and 5-7wt% Guangxi white mud Place in a mixer and stir for 1-1.2 hours to obtain Mixture A.

Step 2. Put 31-33wt% mullite fine powder, 32-34wt% magnesium-aluminum spinel fine powder and 35-36wt% andalusite fine powder in a mixer, stir for 1-1.2h, Dry at 100-110°C for 1-2 hours, grind until the particle size is ≤0.048mm, and obtain the mixture B.

Step 3: first place the mixture A in the mold, then evenly sprinkle a layer of mixture B on the surface of the pressure head, and machine press it under the condition of 130-140 MPa with the mouth of the bowl facing down, and then press it at 100-100 MPa. drying at 110° C. for 20 to 24 hours, and holding at 1325 to 1350° C. for 5 to 6 hours to prepare a sagger for sintering the mullite-cordierite lithium battery cathode material.

Implementation 3

A mullite-cordierite lithium battery cathode material sintering sagger and a preparation method thereof. The preparation method described in this embodiment is:

Step 1. Mix 32-34wt% mullite particles, 22-24wt% mullite fine powder, 31-33wt% cordierite particles, 4-7wt% dextrin and 5-7wt% Guangxi white mud Place in a mixer and stir for 1-1.2 hours to obtain Mixture A.

Step 2. Put 32-34wt% mullite fine powder, 31-33wt% magnesium-aluminum spinel fine powder and 35-36wt% andalusite fine powder in a mixer, stir for 1-1.2h, Dry at 100-110°C for 1-2 hours, grind until the particle size is ≤0.048mm, and obtain the mixture B.

Step 3: first place the mixture A in the mold, then evenly sprinkle a layer of mixture B on the surface of the pressure head, and machine press it under the condition of 140-150 MPa with the mouth of the bowl facing down, and then press it at 100-100 MPa. Drying at 110°C for 20-24 hours, and heat preservation at 1350-1375°C for 5-6 hours to prepare a sagger for sintering the mullite-cordierite lithium battery cathode material.

Implementation 4

A mullite-cordierite lithium battery cathode material sintering sagger and a preparation method thereof. The preparation method described in this embodiment is:

Step 1. Mix 33-35wt% mullite particles, 23-25wt% mullite fine powder, 30-32wt% cordierite particles, 4-7wt% dextrin and 5-7wt% Guangxi white mud Place in a mixer and stir for 1-1.2 hours to obtain Mixture A.

Step 2. Put 33-35wt% mullite fine powder, 30-32wt% magnesium-aluminum spinel fine powder and 35-36wt% andalusite fine powder in a mixer, stir for 1-1.2h, Dry at 100-110°C for 1-2 hours, grind until the particle size is ≤0.048mm, and obtain the mixture B.

Step 3: Put the mixture A in the mold first, then evenly sprinkle a layer of mixture B on the surface of the pressure head, and machine press it under the condition of 150-160 MPa with the mouth of the bowl facing down, and then press it at 100-100 MPa. Dry at 110°C for 20-24 hours, and keep warm at 1375-1400°C for 5-6 hours to prepare a sagger for sintering the mullite-cordierite lithium battery cathode material.

Compared with the prior art, this specific embodiment has the following advantages:

1. In this specific embodiment, the prepared mixture A is placed in a mould, and a layer of prepared mixture B is sprinkled on the surface of the pressure head, and the mouth of the bowl is machine pressed into shape, and dried and fired to obtain Mo Lithium-cordierite lithium battery positive electrode material sintering sagger (hereinafter referred to as "saggar"), so the process is simple; during the firing process, a dense protective layer is formed on the inner surface of the sagger, which increases the corrosion resistance of the sagger Performance, improve the service life of the sagger.

2. In this specific embodiment, cordierite particles are used as the aggregate, and the crystal structure of the cordierite particles has good thermal shock resistance, so the prepared sagger has excellent thermal shock resistance.

3. The source of raw materials in this specific embodiment is abundant and the cost is low. There is no special equipment requirement in the process of preparing the sagger, and the preparation and firing time is short, so the cost is low and industrial production is easy.

The sagger for sintering the mullite-cordierite lithium battery positive electrode material prepared in this specific embodiment is tested: the yield rate is 99.6-99.9%; the apparent porosity is 8.4-10.4 g·cm ³ ; the bulk density is 2.86- 3.26g·cm ³ ; flexural strength is 10.2-13.2MPa; compressive strength is 42.42-48.47MPa; 900℃ static crucible method slag resistance test erosion index is 2.2-3.7%.

Therefore, this specific embodiment has the characteristics of low cost, simple process and high yield; the prepared mullite-cordierite lithium battery positive electrode material sintering sagger has a large volume density, high compressive strength, and thermal shock resistance Excellent and good corrosion resistance.

Claims (9)

1. A preparation method of a mullite-cordierite lithium battery cathode material sintering sagger, characterized in that the specific steps of the preparation method are: Step 1, mix 30-35wt% mullite particles, 20-25wt% mullite fine powder, 30-35wt% cordierite particles, 4-7wt% dextrin and 5-7wt% Guangxi white mud Place in a mixer and stir for 1-1.2 hours to obtain Mixture A; Step 2. Put 30-35wt% mullite fine powder, 30-35wt% magnesium-aluminum spinel fine powder and 35-36wt% andalusite fine powder in a mixer, stir for 1-1.2h, Dry at 100-110°C for 1-2 hours, grind until the particle size is ≤0.048mm, and obtain the mixture B; Step 3: Put the mixture A in the mold first, then evenly sprinkle a layer of mixture B on the surface of the pressure head, and machine press it under the condition of 120-160 MPa with the mouth of the bowl facing down, and then press it at 100-100 MPa. drying at 110°C for 20 to 24 hours, and holding at 1300 to 1400°C for 5 to 6 hours to prepare a sagger for sintering the mullite-cordierite lithium battery cathode material. 2. The preparation method of the mullite-cordierite lithium battery cathode material sintering sagger according to claim 1, characterized in that the chemical composition of the mullite particles is: Al ₂ O ₃ ≥ 67.3wt% , SiO ₂ ≥ 30.4wt%, Fe ₂ O ₃ ≥ 0.92wt%; the density of the mullite particles is 2.82-2.97g/cm ³ , and the particle size of the mullite particles is ≤ 3mm. 3. The preparation method of the mullite-cordierite lithium battery anode material sintering sagger according to claim 1, characterized in that the chemical composition of the mullite fine powder is: Al ₂ O ₃ ≥ 67.3wt %, SiO ₂ ≥ 30.4wt%, Fe ₂ O ₃ ≥ 0.92wt%; the density of the mullite fine powder is 2.82-2.97g/cm ³ , and the particle size of the mullite fine powder is ≤ 0.088mm. 4. The method for preparing the mullite-cordierite lithium battery anode material sintering sagger according to claim 1, characterized in that the chemical composition of the cordierite particles is: Al ₂ O ₃ ≥ 34.1wt%, SiO ₂ ≥ 42.2 wt %, MgO ≥ 14.3 wt %; the density of the cordierite particles is 2.67-2.79 g/cm ³ , and the particle size of the cordierite particles is ≤ 3 mm. 5. The preparation method of the mullite-cordierite lithium battery anode material sintering sagger according to claim 1, characterized in that the particle size of the dextrin is ≤0.088mm. 6. The method for preparing the mullite-cordierite lithium battery anode material sintering sagger according to claim 1, characterized in that the chemical composition of the Guangxi white clay is: Al ₂ O ₃ ≥ 35.2wt%, SiO ₂ content ≥ 48.1wt%, K ₂ O ≥ 2.1wt%; the particle size of the Guangxi white clay ≤ 0.088mm. 7. The preparation method of the mullite-cordierite lithium battery anode material sintering sagger according to claim 1, characterized in that the chemical composition of the magnesium aluminum spinel fine powder: MgO content ≥ 46.3wt% , Al ₂ O ₃ content ≥ 46.2wt%; the particle size of the magnesium aluminum spinel fine powder ≤ 0.088mm. 8. The preparation method of the mullite-cordierite lithium battery cathode material sintering sagger according to claim 1, characterized in that the chemical composition of the andalusite fine powder is: Al ₂ O ₃ ≥ 61.8wt% , SiO ₂ ≥ 29.7; the particle size of the andalusite fine powder ≤ 0.088mm. 9. A mullite-cordierite lithium battery anode material sintering sagger, characterized in that the mullite-cordierite lithium battery anode material sintering sagger is according to any one of claims 1 to 8 A sagger for sintering mullite-cordierite lithium battery positive electrode materials prepared by the method for preparing a mullite-cordierite lithium battery positive electrode material.