阅读说明：本技术 一种基于堇青石的匣钵及其生产工艺 (Sagger based on cordierite and production process thereof ) 是由 何江 于 2021-11-11 设计创作，主要内容包括：本发明涉及一种基于堇青石的匣钵及其生产工艺,包括本体和本体表面的涂层,所述涂层包括涂覆层和致密层,所述涂覆层包括如下重量百分比原料：50-60%刚玉,10-20%尖晶石,5-10%混合粉末,5-10%粘土,余量为二氧化铈粉末；加入填充剂作为烧结用的填充料,其结构为一种负载有氧化锆晶体的三维石墨烯结构,作为填充料与基体料混合后烧结,其特殊的三维结构能够与基体料形成良好的结合层,与基体料紧密的结合,涂覆层以刚玉、尖晶石等作为基料,将其喷涂在坯体表面,形成涂覆层,该涂覆层中含有碳化铬和镍铬合金粉末,碳化铬赋予该涂层优异的抗氧化性能,超高的硬度和优异的耐磨性能,增加匣体的使用寿命。(The invention relates to a sagger based on cordierite and a production process thereof, and the sagger comprises a body and a coating on the surface of the body, wherein the coating comprises a coating layer and a compact layer, and the coating comprises the following raw materials in percentage by weight: 50-60% of corundum, 10-20% of spinel, 5-10% of mixed powder, 5-10% of clay and the balance of cerium dioxide powder; the filler is added to serve as the filler for sintering, the structure of the filler is a three-dimensional graphene structure loaded with zirconia crystals, the filler is mixed with the base material and then sintered, the special three-dimensional structure can form a good bonding layer with the base material and is tightly bonded with the base material, corundum, spinel and the like are used as base materials of the coating layer and are sprayed on the surface of the blank to form the coating layer, chromium carbide and nickel-chromium alloy powder are contained in the coating layer, and the chromium carbide endows the coating layer with excellent oxidation resistance, ultrahigh hardness and excellent wear resistance, so that the service life of the box body is prolonged.)

1. A cordierite-based sagger comprising a body and a coating on a surface of the body, wherein: the body comprises the following raw materials in percentage by weight: 15-30% of cordierite, 10-20% of mullite, 15-30% of aluminum powder, 20-30% of spinel, 1.5-2.5% of bonding agent and the balance of filling agent;

the filler is prepared by the following steps:

step S1, adding graphene oxide into deionized water, dropwise adding a 15% by mass sodium hydroxide aqueous solution to adjust the pH until the pH =10-12, then adding boric acid, stirring at a constant speed for 5min, then adding ethylenediamine, continuously stirring for 5min to obtain a mixed solution, transferring the mixed solution into a reaction kettle, heating to 100-120 ℃, preserving heat, reacting for 6h, and dialyzing in a 15% by volume ethanol aqueous solution for 12h to obtain hydrogel;

step S2, adding zirconium acetate into absolute ethyl alcohol, heating in a water bath at 45-65 ℃, slowly dripping acetylacetone, keeping the temperature for reacting for 1h, then slowly dripping triethylamine, keeping the temperature for reacting for 4h, then cooling to room temperature, dripping acetic acid to adjust the pH value until the pH value is =4-6, and preparing a precursor solution;

step S3, adding the prepared hydrogel into a precursor solution, heating to 45-65 ℃, soaking for 12h, taking out, placing the hydrogel into a dilute hydrochloric acid solution with the mass fraction of 15%, soaking and stirring for 12h, transferring the hydrogel into a reaction kettle, adding deionized water, reacting for 6h at 180 ℃, taking out after the reaction is finished, washing the hydrogel with deionized water until the filtrate is neutral, dialyzing for 12h with an ethanol solution with the volume fraction of 10%, and freeze-drying for 12h to obtain the filling agent.

2. The cordierite-based sagger of claim 1, wherein: the coating comprises a coating layer and a compact layer, wherein the coating layer comprises the following raw materials in percentage by weight: 50-60% of corundum, 10-20% of spinel, 5-10% of mixed powder, 5-10% of clay and the balance of cerium dioxide powder.

3. A cordierite-based sagger as claimed in claim 2, wherein: the mixed powder is formed by mixing chromium carbide and nichrome powder according to the weight ratio of 5: 1.

4. The cordierite-based sagger of claim 1, wherein: the binding agent is formed by mixing silicon dioxide, boron oxide and potassium oxide according to the weight ratio of 5: 3: 2.

5. The process for producing a cordierite-based sagger of claim 2, wherein: the method comprises the following steps:

grinding cordierite, mullite, aluminum powder and spinel, uniformly mixing to obtain a coarse material, adding a binding agent, uniformly stirring at a constant speed of 200r/min for 1min at a speed of 150-;

secondly, mixing and grinding corundum, spinel, mixed powder and clay, then adding the mixture and cerium dioxide powder into a ball milling tank, controlling the ball-material ratio to be 10: 1, adding absolute ethyl alcohol, carrying out ball milling for 20 hours, and drying to obtain spraying powder;

thirdly, heating the blank to 100-130 ℃, and spraying the spraying powder on the surface of the blank by a spray gun to form a coating layer;

and fourthly, adding metal zirconium into a mixing tank, placing bromine into a constant temperature groove at 0 ℃, adding argon as a carrier gas, bubbling, introducing into the mixing tank, sequentially introducing hydrogen and propane, uniformly mixing, then sending into a reaction furnace, reacting for 4 hours at 550 ℃ to obtain a precursor, depositing the precursor on the surface of the coating layer at 1150-1250 ℃, wherein the deposition pressure is less than 20kPa to form a compact layer, the carrier gas flow of the argon is controlled to be 15-50mL/min, the concentration of the introduced hydrogen is 50-75% of the volume of the mixing tank, and the molar ratio of the propane to the bromine is 0.75-1: 1.

6. The process for producing a cordierite-based sagger of claim 5, wherein: in the first step, the amount of water is controlled to be 20% of the weight of the bulk mixture.

7. The process for producing a cordierite-based sagger of claim 5, wherein: the spraying thickness of the coating layer is 0.05-0.1mm, and the thickness of the compact layer is 0.5-10 μm.

Technical Field

The invention belongs to the technical field of saggars, and particularly relates to a saggar based on cordierite and a production process thereof.

Background

The lithium ion battery has wide application prospect in a plurality of fields such as electronic devices, electric vehicles, military affairs, aerospace and the like due to the advantages of high voltage, large energy density, good reversibility and the like. The lithium ion battery anode material is an important part for forming the lithium ion battery, and in the actual production, the high-temperature solid-phase synthesis method is a main method for preparing the lithium ion battery anode material due to simple process and low equipment requirement. The sagger is used as a container for containing raw materials in the high-temperature roasting process, and plays an important role in the normal production of the lithium ion battery anode material. With the increasing demand of lithium battery materials and the development trend of high voltage direction, stricter requirements are provided for the performance of the saggar, particularly the erosion resistance and the thermal shock stability.

The traditional cordierite sagger prepared by the traditional process has a plurality of defects, firstly, the traditional cordierite sagger has high porosity and small volume density, internal impurity components are high, the traditional cordierite sagger is easy to chemically react with active elements in a lithium battery at high temperature, so that the service life of the sagger is not long, the sagger is easy to corrode, and stripping substances of the sagger fall into a positive electrode material of the lithium battery due to corrosion, so that the purity of the positive electrode material is influenced.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a cordierite-based sagger and a process for producing the same.

The purpose of the invention can be realized by the following technical scheme:

a cordierite-based sagger comprises a body and a coating on the surface of the body, wherein the body comprises the following raw materials in percentage by weight: 15-30% of cordierite, 10-20% of mullite, 15-30% of aluminum powder, 20-30% of spinel, 1.5-2.5% of bonding agent and the balance of filling agent;

the filler is prepared by the following steps:

step S1, adding graphene oxide into deionized water, dropwise adding a sodium hydroxide aqueous solution with the mass fraction of 15% to adjust the pH until the pH is =10-12, then adding boric acid, stirring at a constant speed for 5min, then adding ethylenediamine, continuously stirring for 5min to prepare a mixed solution, transferring the mixed solution into a reaction kettle, heating to 120 ℃ at 100 ℃, preserving heat, reacting for 6h, dialyzing in an ethanol aqueous solution with the volume fraction of 15% after reacting for 12h to prepare hydrogel, and controlling the weight ratio of the graphene oxide, the boric acid, the ethylenediamine and the deionized water to be 5-10: 0.3-0.5: 0.8-1.2: 50;

in the step S1, graphene oxide is mixed with boric acid and ethylenediamine in an alkaline environment, and under the combined action of the induction of the ethylenediamine and the borate crosslinking, the pi-pi bonds of the graphene oxide are stacked and self-assembled to form a three-dimensional hydrogel structure with a stable structure;

step S2, adding zirconium acetate into absolute ethyl alcohol, heating in a water bath at 45-65 ℃, slowly dripping acetylacetone, keeping the temperature for reacting for 1h, then slowly dripping triethylamine, keeping the temperature for reacting for 4h, then cooling to room temperature, dripping acetic acid to adjust the pH value until the pH value is =4-6, preparing a precursor solution, and controlling the molar ratio of zirconium acetate to acetylacetone to be 1.5-2: 1 and the molar ratio of triethylamine to zirconium acetate to be 5: 1;

in the step S2, a precursor solution is prepared from zirconium acetate, and the precursor solution is a zirconium oxide precursor solution;

step S3, adding the prepared hydrogel into a precursor solution, heating to 45-65 ℃, preventing the precursor solution from separating out crystals at low temperature, soaking for 12h, taking out, placing the precursor solution into a dilute hydrochloric acid solution with the mass fraction of 15%, soaking and stirring for 12h, then transferring to a reaction kettle, adding deionized water, reacting for 6h at 180 ℃, taking out after the reaction is finished, washing with the deionized water until the filtrate is neutral, then dialyzing for 12h with an ethanol solution with the volume fraction of 10%, and freeze-drying for 12h to obtain the filler, wherein the weight ratio of the hydrogel to the precursor solution is controlled to be 5-7.5: 15-20.

And step S3, adding the prepared hydrogel into a precursor solution for soaking, loading part of the precursor on the hydrogel, enabling a zirconium oxide crystal to grow on a graphene sheet layer with a three-dimensional structure, and then diluting to be neutral, so that the problem that the graphene hydrogel framework is shrunk due to overhigh acidity in the dialysis and freeze drying processes to cause difficulty in molding is prevented, and finally the filling agent is prepared.

Further: the coating comprises a coating layer and a compact layer, wherein the coating layer comprises the following raw materials in percentage by weight: 50-60% of corundum, 10-20% of spinel, 5-10% of mixed powder, 5-10% of clay and the balance of cerium dioxide powder.

Further: the binding agent is formed by mixing silicon dioxide, boron oxide and potassium oxide according to the weight ratio of 5: 3: 2.

A process for producing a cordierite-based sagger, comprising the steps of:

grinding cordierite, mullite, aluminum powder and spinel, uniformly mixing to obtain a coarse material, adding a binding agent, uniformly stirring at a constant speed of 200r/min for 1min at a speed of 150-;

secondly, mixing and grinding corundum, spinel, mixed powder and clay, then adding the mixture and cerium dioxide powder into a ball milling tank, controlling the ball-material ratio to be 10: 1, adding absolute ethyl alcohol as a control agent, carrying out ball milling for 20 hours, and drying to obtain spraying powder;

thirdly, heating the blank to 100-130 ℃, preventing the temperature from being too low, enabling the coating to crack during spraying, spraying the spraying powder on the surface of the blank through a spray gun to form a coating layer, controlling the fuel of the spray gun to be propane, supporting combustion by adopting air, and feeding the powder gas to be nitrogen;

and fourthly, adding metal zirconium into a mixing tank, placing bromine into a constant temperature groove at 0 ℃, adding argon as a carrier gas, bubbling, introducing into the mixing tank, sequentially introducing hydrogen and propane, uniformly mixing, then sending into a reaction furnace, reacting for 4 hours at 550 ℃ to obtain a precursor, depositing the precursor on the surface of the coating layer at 1150-1250 ℃, wherein the deposition pressure is less than 20kPa to form a compact layer, the carrier gas flow of the argon is controlled to be 15-50mL/min, the concentration of the introduced hydrogen is 50-75% of the volume of the mixing tank, and the molar ratio of the propane to the bromine is 0.75-1: 1.

The method comprises the following steps of reacting metal zirconium with bromine in a reaction furnace to generate a zirconium precursor, using the zirconium precursor as a zirconium source, oxidizing at a high temperature to form zirconium oxide, adding propane as a carbon source, and performing vapor deposition to form a zirconium carbide coating, namely a compact layer, so that the zirconium carbide coating has excellent high-temperature resistance.

Further: in the first step, the amount of water is controlled to be 20% of the weight of the bulk mixture.

Further: the spraying thickness of the coating layer is 0.05-0.1mm, and the thickness of the compact layer is 0.5-10 μm.

Further: the mixed powder is formed by mixing chromium carbide and nichrome powder according to the weight ratio of 5: 1.

The invention has the beneficial effects that:

a sagger based on cordierite comprises a body and a double-layer coating on the surface of the body, wherein the body takes cordierite, mullite and the like as raw materials, a filler is added as a filler for sintering, the structure of the body is a three-dimensional graphene structure loaded with zirconia crystals, the filler is mixed with a base material and then sintered, a good bonding layer can be formed by a special three-dimensional structure of the body and the base material, the three-dimensional structure is tightly combined with the base material, then sintering is carried out, the filler forms nano ceramic, the sagger has excellent high temperature resistance and good corrosion resistance, impurities are not introduced, the influence on the sagger body is avoided, but the graphene with the three-dimensional structure has certain pores, so the double-layer coating is prepared, the coating takes corundum, spinel and the like as the base material, and is sprayed on the surface of a blank through high-speed gas spraying to form the coating, the coating layer contains chromium carbide and nickel-chromium alloy powder, the chromium carbide endows the coating with excellent oxidation resistance, ultrahigh hardness and excellent wear resistance, the service life of the saggar is prolonged, then a vapor deposition method is adopted, a uniform compact layer with the thickness of 0.5-10 mu m is deposited on the surface of the coating layer, the ultrathin thickness and the high temperature resistance can reduce the phenomenon that the service life of the saggar is not long due to the fact that impurity components and active elements in a lithium battery chemically react at high temperature, on the other hand, the porosity of the saggar can be reduced, and the leakage of the impurity components is further reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of a process for producing a cordierite-based sagger of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The filler is prepared by the following steps:

step S1, adding graphene oxide into deionized water, dropwise adding a sodium hydroxide aqueous solution with the mass fraction of 15% to adjust the pH until the pH is =10, then adding boric acid, stirring at a constant speed for 5min, then adding ethylenediamine, continuously stirring for 5min to obtain a mixed solution, transferring the mixed solution into a reaction kettle, heating to 100 ℃, preserving heat, reacting for 6h, dialyzing in an ethanol aqueous solution with the volume fraction of 15% after reacting for 12h, removing residues such as ethylenediamine and the like to obtain hydrogel, and controlling the weight ratio of the graphene oxide to the boric acid to the ethylenediamine to the deionized water to be 5: 0.3: 0.8: 50;

step S2, adding zirconium acetate into absolute ethyl alcohol, heating in a water bath at 45 ℃, slowly dripping acetylacetone, carrying out heat preservation reaction for 1h, then slowly dripping triethylamine, carrying out heat preservation reaction for 4h, then cooling to room temperature, dripping acetic acid to adjust pH until pH =4, and preparing a precursor solution, wherein the molar ratio of zirconium acetate to acetylacetone is controlled to be 1.5: 1, and the molar ratio of triethylamine to zirconium acetate is controlled to be 5: 1;

step S3, adding the prepared hydrogel into a precursor solution, heating to 45 ℃, preventing the precursor solution from separating out crystals at a low temperature, soaking for 12 hours, taking out, placing the precursor solution into a dilute hydrochloric acid solution with a mass fraction of 15%, soaking and stirring for 12 hours, then transferring to a reaction kettle, adding deionized water, reacting for 6 hours at 180 ℃, taking out after the reaction is finished, washing with the deionized water until the filtrate is neutral, then dialyzing for 12 hours with an ethanol solution with a volume fraction of 10%, and freeze-drying for 12 hours to obtain a filler, wherein the weight ratio of the hydrogel to the precursor solution is controlled to be 5: 15.

Example 2

The filler is prepared by the following steps:

step S1, adding graphene oxide into deionized water, dropwise adding a sodium hydroxide aqueous solution with the mass fraction of 15% to adjust the pH value until the pH value is =11, then adding boric acid, stirring at a constant speed for 5min, then adding ethylenediamine, continuously stirring for 5min to obtain a mixed solution, transferring the mixed solution into a reaction kettle, heating to 110 ℃, preserving the temperature, reacting for 6h, dialyzing in an ethanol aqueous solution with the volume fraction of 15% after the reaction for 12h, removing residues such as ethylenediamine and the like to obtain hydrogel, and controlling the weight ratio of the graphene oxide, the boric acid, the ethylenediamine and the deionized water to be 8: 0.4: 1.0: 50;

step S2, adding zirconium acetate into absolute ethyl alcohol, heating in a water bath at 50 ℃, slowly dripping acetylacetone, carrying out heat preservation reaction for 1h, then slowly dripping triethylamine, carrying out heat preservation reaction for 4h, then cooling to room temperature, dripping acetic acid to adjust pH until pH =5, and preparing a precursor solution, wherein the molar ratio of zirconium acetate to acetylacetone is controlled to be 1.8: 1, and the molar ratio of triethylamine to zirconium acetate is controlled to be 5: 1;

step S3, adding the prepared hydrogel into a precursor solution, heating to 55 ℃, preventing the precursor solution from separating out crystals at a low temperature, soaking for 12 hours, taking out, placing the precursor solution into a dilute hydrochloric acid solution with a mass fraction of 15%, soaking and stirring for 12 hours, then transferring to a reaction kettle, adding deionized water, reacting for 6 hours at 180 ℃, taking out after the reaction is finished, washing with the deionized water until the filtrate is neutral, then dialyzing for 12 hours with an ethanol solution with a volume fraction of 10%, and freeze-drying for 12 hours to obtain a filler, wherein the weight ratio of the hydrogel to the precursor solution is controlled to be 6.5: 18.

Example 3

The filler is prepared by the following steps:

step S1, adding graphene oxide into deionized water, dropwise adding a 15% sodium hydroxide aqueous solution by mass fraction to adjust the pH until the pH is =12, then adding boric acid, stirring at a constant speed for 5min, then adding ethylenediamine, continuously stirring for 5min to obtain a mixed solution, transferring the mixed solution into a reaction kettle, heating to 120 ℃, preserving the temperature, reacting for 6h, dialyzing in a 15% ethanol aqueous solution by volume fraction for 12h after the reaction, removing residues such as ethylenediamine and the like to obtain hydrogel, and controlling the weight ratio of the graphene oxide to the boric acid to the ethylenediamine to the deionized water to be 10: 0.5: 1.2: 50;

step S2, adding zirconium acetate into absolute ethyl alcohol, heating in a water bath at 65 ℃, slowly dripping acetylacetone, carrying out heat preservation reaction for 1h, then slowly dripping triethylamine, carrying out heat preservation reaction for 4h, then cooling to room temperature, dripping acetic acid to adjust pH until pH =6, and preparing a precursor solution, wherein the molar ratio of zirconium acetate to acetylacetone is controlled to be 2: 1, and the molar ratio of triethylamine to zirconium acetate is controlled to be 5: 1;

step S3, adding the prepared hydrogel into a precursor solution, heating to 65 ℃, preventing the precursor solution from separating out crystals at a low temperature, soaking for 12 hours, taking out, placing the precursor solution into a dilute hydrochloric acid solution with a mass fraction of 15%, soaking and stirring for 12 hours, then transferring to a reaction kettle, adding deionized water, reacting for 6 hours at 180 ℃, taking out after the reaction is finished, washing with the deionized water until the filtrate is neutral, then dialyzing for 12 hours with an ethanol solution with a volume fraction of 10%, and freeze-drying for 12 hours to obtain a filler, wherein the weight ratio of the hydrogel to the precursor solution is controlled to be 7.5: 20.

Example 4

Referring to FIG. 1, a cordierite-based sagger includes a body and a coating on the surface of the body, wherein the body comprises the following raw materials by weight percent: 15% of cordierite, 20% of mullite, 30% of aluminum powder, 30% of spinel, 2.5% of a bonding agent and the balance of the filler prepared in the example 1;

the coating comprises a coating layer and a compact layer, wherein the coating layer comprises the following raw materials in percentage by weight: 50% of corundum, 10% of spinel, 5% of mixed powder, 10% of clay and the balance of cerium dioxide powder.

The mixed powder is formed by mixing chromium carbide and nichrome powder according to the weight ratio of 5: 1.

The binding agent is formed by mixing silicon dioxide, boron oxide and potassium oxide according to the weight ratio of 5: 3: 2.

The production process of the cordierite-based sagger comprises the following steps:

grinding cordierite, mullite, aluminum powder and spinel, uniformly mixing to obtain a coarse material, adding a binding agent, uniformly stirring at a rotating speed of 150r/min for 1min, then combining for 3min, adding water, continuously stirring for 3min, adding a filler, continuously stirring for 15min, charging after stirring, ageing for 12h to obtain a body mixture, performing punch forming, and sintering at 1350 ℃ for 18h to obtain a blank for later use;

secondly, mixing and grinding corundum, spinel, mixed powder and clay, then adding the mixture and cerium dioxide powder into a ball milling tank, controlling the ball-material ratio to be 10: 1, adding absolute ethyl alcohol as a control agent, carrying out ball milling for 20 hours, and drying to obtain spraying powder;

thirdly, heating the green body to 100 ℃, preventing the temperature from being too low, and preventing the coating from cracking during spraying, then spraying the spraying powder on the surface of the green body through a spray gun to form a coating layer, controlling the fuel of the spray gun to be propane, supporting combustion by air, and feeding the powder gas to be nitrogen;

and fourthly, adding zirconium metal into a mixing tank, placing bromine into a constant temperature tank at 0 ℃, adding argon as a carrier gas, bubbling, introducing into the mixing tank, sequentially introducing hydrogen and propane, uniformly mixing, then sending into a reaction furnace, reacting for 4 hours at 550 ℃ to obtain a precursor, depositing the precursor on the surface of the coating layer at 1150 ℃, wherein the deposition pressure is less than 20kPa to form a compact layer, the carrier gas flow of the argon is controlled to be 15mL/min, the concentration of the introduced hydrogen is 50% of the volume of the mixing tank, and the molar ratio of the propane to the bromine is 0.75: 1.

The volume density of the sagger prepared in the embodiment is lower than 2.1g/cm³(ii) a The compressive strength is 85-110MPa, and when the sagger is used for synthesizing lithium cobaltate serving as the positive electrode material of the lithium battery at 1050 ℃, the working surface is peeled off when the sagger is used for 80 times in a circulating way.

Example 5

Referring to FIG. 1, a cordierite-based sagger includes a body and a coating on the surface of the body, wherein the body comprises the following raw materials by weight percent: 20% of cordierite, 15% of mullite, 15% of aluminum powder, 20% of spinel, 2% of a bonding agent and the balance of the filler prepared in the embodiment 1;

the coating comprises a coating layer and a compact layer, wherein the coating layer comprises the following raw materials in percentage by weight: 60% of corundum, 10% of spinel, 5% of mixed powder, 10% of clay and the balance of cerium dioxide powder.

The mixed powder is formed by mixing chromium carbide and nichrome powder according to the weight ratio of 5: 1.

The binding agent is formed by mixing silicon dioxide, boron oxide and potassium oxide according to the weight ratio of 5: 3: 2.

The production process of the cordierite-based sagger comprises the following steps:

grinding cordierite, mullite, aluminum powder and spinel, uniformly mixing to obtain a coarse material, adding a binding agent, uniformly stirring at a constant speed of 180r/min for 1min, then combining for 4min, adding water, continuously stirring for 3min, adding a filler, continuously stirring for 18min, charging after stirring, ageing for 12h to obtain a body mixture, performing punch forming, and sintering at 1380 ℃ for 20h to obtain a green body for later use;

secondly, mixing and grinding corundum, spinel, mixed powder and clay, then adding the mixture and cerium dioxide powder into a ball milling tank, controlling the ball-material ratio to be 10: 1, adding absolute ethyl alcohol as a control agent, carrying out ball milling for 20 hours, and drying to obtain spraying powder;

thirdly, heating the green body to 120 ℃, preventing the temperature from being too low, and preventing the coating from cracking during spraying, then spraying the spraying powder on the surface of the green body through a spray gun to form a coating layer, controlling the fuel of the spray gun to be propane, supporting combustion by air, and feeding the powder gas to be nitrogen;

and fourthly, adding metal zirconium into a mixing tank, placing bromine into a constant temperature tank at 0 ℃, adding argon as carrier gas, bubbling, introducing into the mixing tank, sequentially introducing hydrogen and propane, uniformly mixing, then sending into a reaction furnace, reacting for 4 hours at 550 ℃ to prepare a precursor, depositing the precursor on the surface of the coating layer at 1200 ℃, wherein the deposition pressure is less than 20kPa to form a compact layer, the carrier gas flow of the argon is controlled to be 30mL/min, the concentration of the introduced hydrogen is 65% of the volume of the mixing tank, and the molar ratio of the propane to the bromine is 1: 1.

Examining the sagger prepared in this exampleThe bulk density is less than 2.13g/cm³(ii) a The compressive strength is 85-105MPa, and when the sagger is used for synthesizing lithium cobaltate serving as the positive electrode material of the lithium battery at 1050 ℃, the working surface is peeled off when the sagger is used for 82 times in a circulating way.

Example 6

Referring to FIG. 1, a cordierite-based sagger includes a body and a coating on the surface of the body, wherein the body comprises the following raw materials by weight percent: 30% of cordierite, 10% of mullite, 20% of aluminum powder, 25% of spinel, 1.5% of a bonding agent and the balance of the filler prepared in the example 1;

the coating comprises a coating layer and a compact layer, wherein the coating layer comprises the following raw materials in percentage by weight: 60% of corundum, 20% of spinel, 10% of mixed powder, 10% of clay and the balance of cerium dioxide powder.

The mixed powder is formed by mixing chromium carbide and nichrome powder according to the weight ratio of 5: 1.

The binding agent is formed by mixing silicon dioxide, boron oxide and potassium oxide according to the weight ratio of 5: 3: 2.

The production process of the cordierite-based sagger comprises the following steps:

grinding cordierite, mullite, aluminum powder and spinel, uniformly mixing to obtain a coarse material, adding a binding agent, uniformly stirring at a constant speed of 200r/min for 1min, then combining for 5min, adding water, continuously stirring for 3min, adding a filler, continuously stirring for 20min, charging after stirring, ageing for 12h to obtain a body mixture, performing punch forming, and sintering at 1390 ℃ for 24h to obtain a blank for later use;

secondly, mixing and grinding corundum, spinel, mixed powder and clay, then adding the mixture and cerium dioxide powder into a ball milling tank, controlling the ball-material ratio to be 10: 1, adding absolute ethyl alcohol as a control agent, carrying out ball milling for 20 hours, and drying to obtain spraying powder;

thirdly, heating the green body to 130 ℃, preventing the temperature from being too low, and preventing the coating from cracking during spraying, then spraying the spraying powder on the surface of the green body through a spray gun to form a coating layer, controlling the fuel of the spray gun to be propane, supporting combustion by air, and feeding the powder gas to be nitrogen;

and fourthly, adding metal zirconium into a mixing tank, placing bromine into a constant temperature groove at 0 ℃, adding argon as carrier gas, bubbling, introducing into the mixing tank, sequentially introducing hydrogen and propane, uniformly mixing, then sending into a reaction furnace, reacting for 4 hours at 550 ℃ to prepare a precursor, depositing the precursor on the surface of the coating layer at 1250 ℃, wherein the deposition pressure is less than 20kPa to form a compact layer, the carrier gas flow of the argon is controlled to be 50mL/min, the concentration of the introduced hydrogen is 75% of the volume of the mixing tank, and the molar ratio of the propane to the bromine is 1: 1.

The volume density of the sagger prepared by the embodiment is detected to be lower than 2.03g/cm³(ii) a The compressive strength is 83-110MPa, and when the sagger is used for synthesizing lithium cobaltate serving as the positive electrode material of the lithium battery at 1050 ℃, the working surface is peeled off when the sagger is used for 78 times in a circulating way.

Comparative example 1

This comparative example is a comparison of example 4, with no filler, to produce a sagger having a bulk density of less than 2.35g/cm³(ii) a The compressive strength is 80-92MPa, and when the sagger is used for synthesizing lithium cobaltate serving as the positive electrode material of the lithium battery at 1050 ℃, the working surface is peeled off when the sagger is used for 55 times in a circulating way.

Comparative example 2

This comparative example is a cordierite sagger from a commercial Zibo refractory company having a bulk density of less than 2.52g/cm³(ii) a The compressive strength is 80-95MPa, and when the sagger is used for synthesizing lithium cobaltate serving as the positive electrode material of the lithium battery at 1050 ℃, the working surface is peeled off when the sagger is used for 53 times in a circulating way.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is merely exemplary and illustrative of the principles of the present invention and various modifications, additions and substitutions of the specific embodiments described herein may be made by those skilled in the art without departing from the principles of the present invention or exceeding the scope of the claims set forth herein.