CN109467422B

CN109467422B - Special high-cycle special ceramic crucible for lithium battery and preparation method thereof

Info

Publication number: CN109467422B
Application number: CN201810358718.6A
Authority: CN
Inventors: 李军秀; 黄兵
Original assignee: Hunan Dejingyuan Technology Co ltd
Current assignee: Hunan Dejingyuan Technology Co ltd
Priority date: 2018-04-20
Filing date: 2018-04-20
Publication date: 2021-07-02
Anticipated expiration: 2038-04-20
Also published as: CN109467422A

Abstract

The invention provides a special high-cycle ceramic crucible special for a lithium battery, which comprises a surface working layer and a substrate layer, wherein the surface working layer comprises kaolin, white corundum, alumina micro powder, fused mullite, a binder, spodumene powder, cordierite and water, and the substrate layer comprises sintered mullite, kaolin, alumina micro powder, magnesium carbonate, cordierite, talc, fused magnesia alumina spinel, andalusite, the binder and water. According to the invention, the working layer material on the surface of the crucible adopts fine corrosion-resistant material particles as a main material, the base layer material adopts a material with small thermal expansion coefficient and high temperature resistance as a main material, so that the time for peeling and sticking the bottom is reduced, the side surface and bottom cracking phenomenon is solved, the crucible blank has certain strength, the blank is dried and then placed in a kiln for sintering, the flatness of the bottom of the sintered crucible is better than that of other kilns, and the production in a full-automatic flow line production mode of a user can be met.

Description

Special high-cycle special ceramic crucible for lithium battery and preparation method thereof

Technical Field

The invention belongs to the technical field of lithium battery materials, and particularly relates to a special high-cycle ceramic crucible special for a lithium battery and a preparation method thereof.

Background

The anode material of the lithium battery must be roasted in a high-temperature kiln, and a crucible is adopted for loading in the sintering process.

Crucible materials used in China are roughly classified into five types in terms of materials: alumino-silica crucibles, alumino-silica-magnesia crucibles, semi-siliceous crucibles, clay-fused silica crucibles and silicon carbide crucibles. The crucible material for producing the lithium ion battery anode material mainly comprises mullite or mullite-cordierite and corundum-mullite. At present, in the actual production of synthesizing the lithium ion battery anode material, a high-temperature solid-phase synthesis method is generally adopted, and the high-temperature solid-phase synthesis method has simple process and low requirement on equipment and is suitable for large-scale production. The method comprises the steps of directly stirring and mixing required raw materials in a solid state through a machine at a high speed, then roasting at a high temperature, cooling, crushing and sieving to obtain the product. In the high-temperature roasting process, the crucible is required to have high erosion resistance because the erosion of the anode raw material to the crucible is large. The existing crucible material mainly has the following problems: (1) the service life is short. The crucible used in the process of synthesizing the lithium ion battery anode material is generally a corundum crucible, a mullite crucible, a quartz crucible and a cordierite crucible which are resistant to high temperature, because the raw material for synthesizing the lithium ion battery anode material can be decomposed in the synthesis process to generate lithium oxide with strong permeability and reaction activity, and the lithium oxide has an erosion effect on the crucible which is resistant to high temperature, in addition, when the crucible material is rapidly cooled after high temperature, cracks are easily generated along with the increase of the using times, the thermal shock stability of the crucible is damaged, and finally the service life of the crucible which is resistant to high temperature is greatly reduced; (2) the crucible material has poor erosion resistance. The corrosion resistance is an important index of the lithium ion battery anode material in the synthesis process, and in the process of contacting the lithium ion with the crucible, the lithium ion can separate out Si, Al, Mg and other ions in the crucible, so that the microstructure of the crucible is damaged, the crucible is corroded, and a bluish-white corrosion layer appears on the surface of the crucible, so that the service life of the crucible is shortened; (3) the thermal shock stability of the crucible becomes poor. When the crucible is used at high temperature in a kiln, certain sintering changes continue to occur, so that the volume of the crucible expands or contracts, and the crucible cracks due to irreversible volume changes; (4) the crucible has low strength. The crucible is usually put into the kiln in double layers or multiple layers, and with the improvement of automation degree, the crucible bears the weight of the crucible and the weight of the synthetic materials and is also subjected to mechanical acting force of getting in and out of the kiln and loading and unloading the materials, so the crucible needs to have enough mechanical strength. At high temperatures, insufficient strength causes plastic deformation of the crucible, so that the crucible requires sufficient high-temperature mechanical strength, high refractoriness under load, and creep resistance; (5) the crucible material is easy to peel, drop slag and pollute products. During the use process of the crucible, the lithium-containing compound is corroded to the crucible before the cobalt-containing compound to form a composite compound and precipitate the composite compound, so that peeling and even falling-off phenomena are generated, and the product is polluted.

The domestic crucible is mainly from Japan, Korea and domestic products, and the crucible material is the most excellent in the process of use, and the second time in Korea is the worst in the domestic products. In the using process of the Japanese-Korean crucible on the roller kiln, the service life is about 25-30 times, the selling price of a single crucible is 200-300 yuan, and on the push plate kiln, the crucible cracks after being fed back and used for several times. The corrosion resistance and energy saving and consumption reduction of domestic crucibles do not reach the domestic medium level basically, most manufacturers adopt a manual mould beating or simple mechanical friction vibration forming process, and mainly play a low-quality and low-price production and sales mode. The crucible produced by each manufacturer has the phenomena of peeling, falling, deformation, cracking and bottom material sticking more or less along with the increase of the use times, so that great potential safety hazards are brought to the product quality, the domestic crucible can not meet the production requirements more and more along with the large-scale use of a domestic automatic production line and a Japanese-Korean kiln roller way, the flatness gap at the bottom of the crucible is required to be less than or equal to 1.5 mm by the automatic production line of the roller way kiln, and the flatness gap at the bottom of the crucible can be guaranteed to be not more than 2mm by the domestic manufacturer, so that great potential safety hazards are brought to the roller way kiln production process.

With the appearance and development of various novel lithium ion battery anode materials, the development of high-voltage lithium cobalt oxide, high-nickel binary and nickel-cobalt-aluminum, and the high activity of the electric automobile market, the demand of the crucible for the lithium ion battery anode material is increasing day by day. Along with the improvement of the automation degree of the anode material preparation industry, new requirements are put forward on the performance of the crucible material. The crucible material should have good erosion resistance, thermal shock stability, distortion resistance, atmosphere adaptability and certain strength, and in addition, the crucible material cannot peel and drop slag in the using process and cannot bring magnetic foreign matters to pollute products.

CN105669223A discloses a crucible for roasting a lithium battery anode material, which comprises a bottom surface and a side wall, wherein the bottom surface and the side wall form a concave cavity for roasting, the crucible comprises a base body and a working layer, the working layer is arranged on the working surface of the base body, the base body comprises mullite, corundum, kaolin, alumina powder, quartz and cordierite, the working layer comprises potash feldspar, fused quartz, mullite, andalusite, corundum, alumina powder and zirconia powder, and when the crucible is manufactured, the working layer is firstly laminated on the working surface of the base body in a dry forming mode. The invention can effectively prolong the service life of the crucible for roasting the lithium battery anode material and reduce the manufacturing cost. CN102491773A discloses a high-crystal mullite-cordierite high-temperature industrial ceramic and a production method thereof, wherein raw materials comprise a main crystal phase material, a combined composite matrix material and a proper amount of composite microcrystalline nucleating agent, and a roasting process comprises a two-stage constant-temperature sintering method and a two-stage composite crystallization synthesis reaction. CN103311498A discloses a roasting crucible and a preparation method thereof, the preparation method comprises the steps of mixing mullite, cordierite, alumina, corundum, kaolin, active magnesium oxide, spodumene and a binding agent uniformly and pressing the mixture into a green body, mixing zirconia, spodumene, cerium oxide, corundum and the binding agent uniformly, enabling the mixture to be distributed on the surface of the green body uniformly, pressing the mixture again through equipment to obtain a semi-finished crucible product, and finally drying and firing the semi-finished crucible product.

In summary, there is still a need to develop a crucible that can be widely applied to the anode material of a lithium ion battery, and the crucible has a long service life, good material erosion resistance, good strength, good thermal shock resistance, and is not easy to peel and slag, and can satisfy the production of a user full-automatic flow line production mode.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide a special high-cycle ceramic crucible special for a lithium battery.

The invention also aims to provide a preparation method of the crucible.

In order to achieve the purpose, the invention adopts the following technical scheme:

the special high-cycle special ceramic crucible for the lithium battery comprises fine particle corrosion resistanceThe corrosion-resistant material comprises a surface working layer taking corrosion materials as main materials and a base layer taking high-temperature-resistant materials with small thermal expansion coefficients as main materials, wherein the particle size range of the fine-particle corrosion-resistant materials is 0-2 mm, the thickness of the surface working layer is larger than 2mm, and the thermal expansion coefficient range of the base layer main materials is (2.8-3.2) multiplied by 10^-6The high temperature resistant range is less than or equal to 1300 ℃.

Preferably, the surface working layer comprises the following raw materials in parts by weight:

5-30 parts of kaolin clay,

30-70 parts of white corundum,

5-15 parts of aluminum oxide,

5-60 parts of mullite,

1-5 parts of a binder,

2-10 parts of spodumene powder,

1-20 parts of cordierite,

1-5 parts of water.

Preferably, the base layer comprises the following raw materials in parts by weight:

10-60 parts of mullite,

5-20 parts of kaolin clay,

0 to 10 parts of aluminum oxide,

1-10 parts of magnesium carbonate,

10-50 parts of cordierite,

5-20 parts of talcum,

0 to 10 parts of magnesium aluminate spinel,

0 to 10 parts of andalusite,

1-5 parts of a binder,

1-5 parts of water.

Preferably, the white corundum is white corundum particles of 100-325 meshes and white corundum powder of 10-100 meshes according to the weight ratio of (0.1-0.5): 1.

Preferably, the mullite is fused mullite M70.

Preferably, the mullite is 0.1-1 mm of M45 sintered mullite and 1-5 mm of M45 sintered mullite in a weight ratio of (0.1-0.5): 1.

Preferably, the binder is yellow dextrin, and the alumina is alpha-alumina micropowder.

Preferably, the cordierite in the substrate layer is cordierite with a mesh size of less than 8 meshes and cordierite with a mesh size of 300-355 meshes in a weight ratio of 1: (0.1-0.5).

A preparation method of a special high-cycle ceramic crucible special for a lithium battery comprises the following steps:

(1) weighing raw materials of the surface working layer according to a ratio, dissolving yellow dextrin in water, mixing kaolin, white corundum, alumina micro powder, fused mullite, spodumene powder and cordierite, adding a pre-dissolved yellow dextrin solution, and mixing;

(2) weighing the raw materials of the substrate layer according to the proportion, dissolving yellow dextrin in water, mixing sintered mullite, kaolin, alumina micro powder, magnesium carbonate, cordierite, talc, fused magnesia-alumina spinel and andalusite, adding a pre-dissolved yellow dextrin solution, and uniformly mixing;

(3) adding the surface working layer material prepared in the step (1) to the bottom of a mould, and pressing to obtain a surface working layer;

(4) uniformly distributing the substrate layer material prepared in the step (2) on the whole die, and pressing to obtain a semi-finished product;

(5) and (4) drying and sintering the semi-finished product in the step (4).

Preferably, before the pressing in the step (3), the surface working layer material and the substrate layer material prepared in the steps (1) and (2) are placed in a sealed container for ageing for more than 24 hours.

Preferably, the pressing in the steps (3) and (4) adopts a full-automatic crucible hydraulic forming machine, and the tonnage of the hydraulic machine is more than or equal to 500T.

And (5) drying at the temperature of 50-200 ℃ for more than 12 h.

Preferably, the sintering time in the step (5) is 30-40 h, and the temperature is 1250-1450 ℃.

The crucible is pressed upside down during the pressing process, and the surface working layer of the crucible is in contact with the anode material of the battery during the use process.

The invention has the advantages of

1. According to the invention, the working layer material on the surface of the crucible adopts fine corrosion-resistant material particles as a main material, and the base layer material adopts a material with small thermal expansion coefficient and high temperature resistance as a main material, so that the time of peeling and material sticking at the bottom is slowed down, and the phenomena of side surface and bottom cracking are solved;

2. the crucible blank has certain strength, the blank is dried and then placed into a kiln for sintering, the flatness of the bottom of the sintered crucible is better than that of the bottom of other kilns, and the production of a full-automatic flow line production mode of a user can be met;

3. compared with the prior art, the crucible has the advantages of low porosity, high volume density, good creep resistance, good thermal shock resistance, long service life and the like, and is suitable for high-temperature sintering of the lithium battery anode material.

Drawings

FIG. 1 is a flow chart of the crucible preparation process of the present invention.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

Example 1

The embodiment provides six surface working layer materials A1-F1 and corresponding six base layer materials A2-F2, and the specific formula is shown in Table 1.

TABLE 1A 1-F1 six surface working layer material formulas

TABLE 2A 2-F2 six base layer material formulas

Example 2

The embodiment provides a preparation method of a special high-cycle ceramic crucible for a lithium battery, and the process flow is shown in fig. 1, and the preparation method specifically comprises the following steps:

(5) and (4) drying and sintering the semi-finished product in the step (4).

Before the pressing in the step (3), the surface working layer material and the substrate layer material prepared in the steps (1) and (2) are placed in a sealed container for ageing for more than 24 hours. And (4) pressing by adopting a full-automatic crucible hydraulic forming machine, wherein the tonnage of the hydraulic machine is more than or equal to 500T. And (5) drying at the temperature of 50-200 ℃, for more than 12 hours, firing for 30-40 hours, and at the temperature of 1250-1450 ℃.

Example 3

The six formulas provided by the embodiment 1 and the method provided by the embodiment 2 are adopted to prepare the corresponding A-F six special high-cycle ceramic crucibles for lithium batteries, and before the pressing in the step (3), the surface working layer material and the matrix layer material prepared in the steps (1) and (2) are placed in a sealed container for ageing for more than 24 hours. And (4) pressing by adopting a full-automatic crucible hydraulic forming machine, wherein the tonnage of the hydraulic machine is more than or equal to 500T. And (5) drying at 75 ℃, for more than 12h, for 35h and at 1350 ℃. The room temperature compressive strength and the service life of the crucible are shown in Table 3.

TABLE 3 Normal temperature compressive strength and service life of the crucible

Crucible numbering	Normal temperature compressive strength/MPa	Service life (times)
			A	75	30
B	77	35
			C	88	55
D	95	60
			E	85	45
F	82	40

Comparative example 1

By adopting the formula of the surface working layer D1 and the matrix layer D2 provided in the embodiment 1 and the method provided in the embodiment 2, the corresponding G-I three types of special high-cycle special ceramic crucibles for lithium batteries are prepared.

Before the crucible G is pressed in the step (3), the surface working layer material and the substrate layer material prepared in the steps (1) and (2) are directly pressed without ageing. And (4) pressing by adopting a full-automatic crucible hydraulic forming machine, wherein the tonnage of the hydraulic machine is more than or equal to 500T. And (5) drying at 75 ℃, for more than 12h, for 35h and at 1350 ℃.

Before the crucible H is pressed in the step (3), the surface working layer material and the substrate layer material prepared in the steps (1) and (2) are placed in a sealed container for ageing for 12 hours. And (4) pressing by adopting a full-automatic crucible hydraulic forming machine, wherein the tonnage of the hydraulic machine is more than or equal to 500T. And (5) drying at 75 ℃, for more than 12h, for 35h and at 1350 ℃.

Before the crucible I is pressed in the step (3), the surface working layer material and the substrate layer material which are prepared in the steps (1) and (2) are placed in a sealed container for ageing for more than 24 hours. And (4) pressing by adopting a full-automatic crucible hydraulic forming machine, wherein the tonnage of the hydraulic machine is more than or equal to 500T. And (5) drying at 75 ℃ for more than 12h, sintering at 1500 ℃ for 35 h. The room temperature compressive strength and service life of crucibles A and G to I are shown in Table 4.

TABLE 4 comparison of Normal temperature compressive strength and service life of crucibles

Comparative example 2

This comparative example compares the specific consumption, service life and cost ratios of the inventive crucible and three commercially available crucibles, as shown in table 5.

TABLE 5 comparison of the specific consumption, service life and cost ratios of crucible A and three commercially available crucibles

Claims

1. The special high-cycle special ceramic crucible for the lithium battery is characterized by comprising a surface working layer taking fine-particle corrosion-resistant materials as main materials and a substrate layer taking low-thermal expansion coefficient and high-temperature-resistant materials as main materials, wherein the particle size range of the fine-particle corrosion-resistant materials is 0-2 mm, the thickness of the surface working layer is larger than 2mm, and the thermal expansion coefficient range of the main materials of the substrate layer is (2.8-3.2) multiplied by 10^-6The high temperature resistant range is less than or equal to 1300 ℃;

the base layer is prepared from the following raw materials in parts by weight:

10-60 parts of mullite,

5-20 parts of kaolin clay,

0 to 10 parts of aluminum oxide,

1-10 parts of magnesium carbonate,

10-50 parts of cordierite,

5-20 parts of talcum,

0 to 10 parts of magnesium aluminate spinel,

0 to 10 parts of andalusite,

1-5 parts of a binder,

1-5 parts of water;

the surface working layer comprises the following raw materials in parts by weight:

5-30 parts of kaolin clay,

30-70 parts of white corundum,

5-15 parts of aluminum oxide,

5-60 parts of mullite,

1-5 parts of a binder,

2-10 parts of spodumene powder,

1-20 parts of cordierite,

1-5 parts of water, namely,

the white corundum is white corundum particles of 100-325 meshes and white corundum powder of 10-100 meshes according to the weight ratio of (0.1-0.5): 1 of a mixture of (a) and (b),

wherein the mullite in the surface working layer is electrofused mullite M70, the mullite in the substrate layer is 0.1-1 mm of M45 sintered mullite and 1-5 mm of M45 sintered mullite in a weight ratio of (0.1-0.5): 1.

2. The crucible of claim 1, wherein the binder is yellow dextrin and the alumina is alpha-alumina micropowder.

3. The preparation method of the special high-cycle ceramic crucible for the lithium battery, which is disclosed by claim 1, is characterized by comprising the following steps of:

(3) placing the surface working layer material prepared in the step (1) in a sealed container for ageing, ageing for more than 24 hours, adding the surface working layer material to the bottom of a mould after ageing, and pressing to obtain a surface working layer;

(4) placing the base layer material prepared in the step (2) in a sealed container for ageing for more than 24 hours, uniformly distributing the base layer material on the whole mold after ageing, and pressing to obtain a semi-finished product;

(5) drying and sintering the semi-finished product obtained in the step (4);

the sintering time in the step (5) is 30-40 h, and the temperature is 1250-1450 ℃.

4. The preparation method of the special high-cycle ceramic crucible for the lithium battery as claimed in claim 3, wherein the drying temperature in the step (5) is 50-200 ℃, and the drying time is more than 12 hours.