CN113387712A - Sagger formula for producing ternary cathode material and production method - Google Patents

Abstract

The invention discloses a sagger formula for producing a ternary cathode material and a production method thereof, wherein the sagger formula for producing the ternary cathode material comprises the following components in percentage by weight: 3-5 wt% of boron nitride and alpha-Al₂O₃ 8-10 wt%, 20-25wt% of large-particle-size cordierite, 10-15 wt% of small-particle-size cordierite, 20-25wt% of mullite, 20-25wt% of kaolin, 3-5 wt% of silicon micropowder and 4-6wt% of bonding agent, wherein the raw materials are subjected to stirring, ageing, mould pressing and drying, and then are fired and formed at the high temperature of 1350-: during green compact pressing, fine-particle-size particles spontaneously migrate to the surface layer to form a surface compact layer with the diameter of 1-2mm, so that the corrosion of each material to the surface layer during the firing of the ternary cathode material is reduced, the material migration space is blocked, and the problem of material adhesion is solved(ii) a Meanwhile, the formula provided by the invention contains a surface lubricating component, so that the surface roughness of a sagger firing part is improved, and the problem of material sticking of a product is further improved.

Description

Sagger formula for producing ternary cathode material and production method

Technical Field

The invention relates to the field of lithium batteries, in particular to a sagger formula for producing a nickel cobalt lithium manganate ternary positive electrode material and a production method thereof.

Background

The performance of a commercial lithium ion battery cathode material is an important factor determining the performance of a lithium ion battery. Currently, developed anode materials include lithium cobaltate, lithium iron phosphate, lithium manganate, ternary materials, and the like. Lithium nickel cobalt manganese oxide is the most common positive electrode material of a ternary lithium battery. Nickel ion (Ni)²⁺) The volume energy density of the anode material can be increased; manganese ion (Mn)⁴⁺) Can improve the heat of the materialThe stability is improved, and the safety performance of the material is further improved; cobalt ion (Co)³⁺) Can make up the deficiency of manganese ions, maintain the stability of the layered structure of the material and further improve the cycle rate performance of the material. Therefore, the ternary lithium battery cathode material gradually becomes the mainstream cathode material of the lithium battery for the vehicle, and is widely applied to the field of new energy electric vehicles.

The ternary positive electrode material is prepared by placing various precursors in a sagger and sintering at high temperature by adopting a high-temperature solid phase method (a pushed slab kiln or a roller kiln). The sagger material for firing is mainly cordierite, mullite and corundum. Sagger in the current market is applied to production of ternary lithium battery anode materials, the ternary anode materials are adhered to the inner surface of the sagger after firing is completed, and more materials are remained and are difficult to remove when the sagger is inverted.

Aiming at the problem of sagger material sticking in the production of ternary cathode materials, few researches are carried out at present, the sagger pouring and cleaning mechanism is mainly improved, but the effect is not ideal.

Disclosure of Invention

The invention aims to provide a sagger formula for producing a ternary cathode material and a production method thereof, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides a sagger formula for producing a ternary cathode material, which adopts the following technical scheme that the sagger formula comprises the following components in percentage by weight: 3-5 wt% of boron nitride and alpha-Al₂O₃ 8-10 wt%, 20-25wt% of large-particle-size cordierite, 10-15 wt% of small-particle-size cordierite, 20-25wt% of mullite, 20-25wt% of kaolin, 3-5 wt% of silicon micropowder and 4-6wt% of binder as a remainder.

Preferably, the ratio of the large-particle-diameter cordierite to the small-particle-diameter cordierite is 2: 1.

Preferably, the boron nitride is granular, the particle size of the boron nitride is 20-50 μm, and the density of the boron nitride is 2.27-2.30g/cm³ 。

Preferably, the granularity of the silicon micro powder is 800-1600 meshes and SiO₂Content (wt.)>85％。

Preferably, the binder is a yellow dextrin solution, and the water content of the binder is 45-55%.

The invention also provides a production method of the sagger for producing the ternary cathode material, which comprises the following steps:

step one, weighing materials according to the weight percentage, placing the materials in a stirrer to be stirred until the materials are uniformly mixed, and ageing the materials for 48 hours to obtain powder, and measuring the water content of the powder after ageing, wherein the water content is between 3 and 5 percent;

secondly, the materials enter a sagger die through a conveyor belt and an automatic feeding device for compression molding, and green bodies are manufactured;

step three, naturally airing the green body, transferring the green body to a drying room, and drying for 48 hours, wherein the baking temperature is controlled to be 90-100 ℃;

and step four, placing the sagger product dried in the step four into a high-temperature kiln for sintering, wherein the sintering temperature is 1350-.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the formula and the production method provided by the invention, coexistence bodies with various particle sizes are formed during burdening, and when green-crushing pressing is carried out, fine-particle-size particles spontaneously migrate to a surface layer along with the gradual increase of the pressure of a die after automatic feeding is finished, so that a surface compact layer with the diameter of 1-2mm is formed. Therefore, the corrosion of each material to the surface layer when the ternary cathode material is fired is reduced, the material migration space is blocked, and the problem of material adhesion is solved;

2. the formula provided by the invention contains an effective surface lubricating component, and can improve the surface roughness of a saggar firing part to a greater extent, so that the problem of material sticking of a product is solved.

Detailed Description

The invention provides a technical scheme that: a sagger formula for producing a ternary cathode material comprises the following components in percentage by weight: 3-5 wt% of boron nitride and alpha-Al₂O₃ 8-10 wt%, 20-25wt% of large-particle-size cordierite, 10-15 wt% of small-particle-size cordierite, 20-25wt% of mullite, 20-25wt% of kaolin, 3-5 wt% of silicon micropowder and 4-6wt% of binder as a remainder.

Understandably, the boron nitride density: 2.27-2.30g/cm³The particle size is 20-50 μm;

the alpha-Al₂O₃ Al of alumina powder₂O₃The content is more than or equal to 98 wt%, and the grain diameter is less than or equal to 0.10 mm;

the particle size range of the large-particle-size cordierite is 0.5-1.5 mm;

the small-particle-size cordierite has the particle size of less than or equal to 0.075 mm;

al of the mullite₂O₃The content is more than or equal to 65 wt%, and the grain diameter is less than or equal to 1.0 mm;

al of the kaolin₂O₃The content is more than or equal to 33 wt%, and the grain diameter is less than or equal to 0.10 mm;

SiO in the silicon micro powder₂The content is more than 85%, and the granularity is 800-1600 meshes;

the binder is yellow dextrin solution with water content of 45-55%.

Wherein the ratio of the large-particle-size cordierite to the small-particle-size cordierite is 2: 1.

The invention also provides a production method of the anti-sticking sagger produced by the ternary cathode material, which comprises the following steps:

step one, weighing materials according to the weight percentage, placing the materials in a stirrer to be stirred until the materials are uniformly mixed, and ageing the materials for 48 hours to obtain powder, and measuring the water content of the powder after ageing, wherein the water content is between 3 and 5 percent;

secondly, the materials enter a sagger die through a conveyor belt and an automatic feeding device for compression molding, and green bodies are manufactured;

step three, naturally airing the green body, transferring the green body to a drying room, and drying for 48 hours, wherein the baking temperature is controlled to be 90-100 ℃;

and step four, placing the sagger product dried in the step four into a high-temperature kiln for sintering, wherein the sintering temperature is 1350-.

Example 1, a sagger formula for producing a ternary cathode material comprises the following components in percentage by mass: boron nitride 3wt%, alpha-Al₂O₃ 10 wt% of cordierite 2 having a large particle diameter5wt%, small-particle-size cordierite 12.5 wt%, mullite 22.5wt%, kaolin 23wt%, fine silica powder 4wt%, and yellow dextrin solution 4wt% (containing water 50 wt%).

Material

Boron nitride

α- Al2O3

Large grain size cordierite

Small particle size cordierite

Mullite

Kaolin clay

Silicon micropowder

Percentage of

3wt％

10wt％

25wt％

12.5wt％

22.5wt %

23wt%

4wt％

A production method of an anti-sticking sagger produced by a ternary cathode material comprises the following steps:

the first step,Boron nitride 3wt%, alpha-Al₂O₃ 10 wt%, 25wt% of large-particle-size cordierite, 12.5 wt% of small-particle-size cordierite, 22.5wt% of mullite, 23wt% of kaolin and 4wt% of silicon micropowder, and adding 4wt% of yellow dextrin solution (containing 50wt% of water) as a binder to mix, placing the mixture in a stirrer to stir until the mixture is uniformly mixed, and ageing for 48 hours to obtain the powder. Measuring the water content of the powder after the aging, wherein the water content is between 3 and 5 percent;

secondly, the materials enter a sagger die through a conveyor belt and an automatic feeding device for compression molding, and green bodies are manufactured;

step three, naturally airing the green body, transferring the green body to a drying room, and drying for 48 hours, wherein the baking temperature is controlled to be 90-100 ℃;

and step four, placing the sagger product dried in the step four into a high-temperature kiln for sintering, wherein the sintering temperature is 1350-.

When the sagger prepared in the embodiment 1 is used for producing the ternary lithium battery cathode material, after the sagger is used for 25 times, the amount of the single sagger binder is 25g, which is far less than the conventional 50g binder.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "disposed," "connected," "secured," "screwed" and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; the terms may be directly connected or indirectly connected through an intermediate, and may be communication between two elements or interaction relationship between two elements, unless otherwise specifically limited, and the specific meaning of the terms in the present invention will be understood by those skilled in the art according to specific situations.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (6)

1. A sagger formula for producing a ternary cathode material and a production method are characterized in that the sagger formula comprises the following components in percentage by weight: 3-5 wt% of boron nitride and alpha-Al₂O₃ 8-10 wt%, 20-25wt% of large-particle-size cordierite, 10-15 wt% of small-particle-size cordierite, 20-25wt% of mullite, 20-25wt% of kaolin, 3-5 wt% of silicon micropowder and 4-6wt% of binder as a remainder.

2. The sagger formulation for ternary positive electrode material production of claim 1, wherein: the ratio of the large-particle-size cordierite to the small-particle-size cordierite is 2: 1.

3. The sagger formulation for ternary positive electrode material production of claim 1, wherein: the boron nitride is granular, the particle size of the boron nitride is 20-50 mu m, and the density of the boron nitride is 2.27-2.30g/cm³。

4. The sagger formulation for ternary positive electrode material production of claim 1, wherein: the granularity of the silicon micro powder is 800-1600 meshes and SiO₂Content (wt.)>85％ 。

5. The sagger formulation for ternary positive electrode material production of claim 1, wherein: the binder is yellow dextrin solution, and the water content of the binder is 45-55%.

6. A method for producing a sagger for ternary positive electrode material production according to any one of claims 1 to 5, characterized in that it comprises the following steps:

step one, weighing materials according to the weight percentage, placing the materials in a stirrer to be stirred until the materials are uniformly mixed, and ageing the materials for 48 hours to obtain powder, and measuring the water content of the powder after ageing, wherein the water content is between 3 and 5 percent;

secondly, the materials enter a sagger die through a conveyor belt and an automatic feeding device for compression molding, and green bodies are manufactured;

step three, naturally airing the green body, transferring the green body to a drying room, and drying for 48 hours, wherein the baking temperature is controlled to be 90-100 ℃;

and step four, placing the sagger product dried in the step four into a high-temperature kiln for sintering, wherein the sintering temperature is 1350-.