Sagger resistant to erosion of lithium battery material and preparation method of sagger

Abstract

The invention provides a sagger resistant to erosion of a lithium battery material and a preparation method of the sagger. The preparation method comprises the following steps: (1) carrying out first mixing on magnesium aluminate spinel aggregate, mullite aggregate and corundum aggregate to obtain mixed aggregate; (2) adding magnesium aluminate spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay and lithium silicon aluminum oxide into the mixed aggregate, and performing secondary mixing to obtain a premix; (3) adding an adhesive and a solvent into the premix to obtain a mixture; (4) sealing and ageing the mixture; performing compression molding; and sintering to obtain the sagger resistant to erosion of the lithium battery material. The lithium silicon aluminum oxide, the magnesium aluminate spinel, the mullite and the corundum are used as matrix materials, so that the lithium corrosion resistance of the sagger is effectively improved, reverse diffusion of heterogeneous elements to a lithium battery material is avoided, the lithium battery material is prevented from being polluted, and chemical corrosion of a high-activity lithium component in an electrode material to the sagger is effectively inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ion batteries, in particular to the preparation of electrode materials, and in particular to a sagger resistant to corrosion by lithium battery materials and a preparation method thereof. Background Art

[0002] Saggers are essential containers for the preparation of lithium-ion battery electrode materials. During the high-temperature synthesis of electrode materials, the lithium element in the electrode material penetrates and diffuses into the interior of the sagger along the pores on the surface of the sagger, reacting with the sagger components to form a reaction layer mainly composed of lithium-containing erosion phases such as LiAlO2, LiAlSiO4, LiAlSi2O6, Li4SiO4 and Li2SiO3. These lithium-containing erosion phases do not match the thermal expansion of the sagger matrix. After repeated use, the reaction layer peels off, causing contamination of the electrode material. Therefore, extending the service life of the sagger is an important technical problem that needs to be solved urgently.

[0003] CN119100766A discloses a filling slurry, a corrosion-resistant, long-life sagger, and its preparation method and application, relating to the field of sagger preparation technology. The raw materials of the filling slurry, calculated on a 100% by mass basis, include: 40%-60% solid aggregate, 25%-35% binder, and the remainder dispersant; the solid aggregate comprises component A and component B; component A comprises one or more of aluminum oxide powder, magnesium oxide powder, zirconium oxide, and silicon oxide; and component B comprises one or more of calcium titanate, calcium zirconate, silicon carbide, and boron carbide. The combination of components A and B increases the mechanical strength of the filling slurry, reduces the thermal expansion coefficient, and enhances corrosion resistance and thermal shock stability.

[0004] CN108658611A discloses a cordierite-bonded calcium hexaaluminate sagger and a preparation method thereof. High-temperature-treated calcium hexaaluminate aggregate is connected via cordierite to form a cordierite-bonded calcium hexaaluminate structure. The firing temperature is close to that of the currently widely used cordierite sagger, facilitating production. Calcium hexaaluminate has excellent alkali corrosion resistance, which improves the corrosion resistance and service life of the sagger.

[0005] CN116924785A discloses a high-performance ceramic sagger and its preparation method. By using wrapping technology, fine materials with good corrosion resistance are wrapped on the surface of modified aggregates with good thermal shock resistance. The resulting sagger has both thermal stability and excellent corrosion resistance, thereby improving the service life of the sagger.

[0006] Therefore, it is of great significance to provide a sagger that has a long service life and does not contaminate electrode materials and a preparation method thereof. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the present invention aims to provide a sagger resistant to lithium battery material corrosion and a preparation method thereof. The present invention uses lithium silicon aluminum oxide and magnesium aluminum spinel, mullite and corundum as matrix materials. During service, it can also react with the active lithium component in the positive electrode material to form a stable LiAlO2 or LiAlSiO4 interface corrosion layer. The corrosion layer can effectively inhibit the chemical corrosion of the highly active lithium component in the electrode material to the sagger. The lithium silicon aluminum oxide reacts with the lithium in the electrode material to form a stable LiAlO2 or LiAlSiO4 interface corrosion layer. + The reaction inertness of the sagger effectively improves the resistance of the sagger to lithium corrosion. At the same time, the addition of lithium silicon aluminum oxide avoids the reverse diffusion of heterogeneous elements into the lithium battery material and prevents the contamination of the lithium battery material.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a sagger resistant to corrosion by lithium battery materials, the preparation method comprising:

[0010] (1) performing a first mixing of magnesia-alumina spinel aggregate, mullite aggregate, and corundum aggregate to obtain a mixed aggregate;

[0011] (2) adding magnesia-alumina spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay and lithium silicon aluminum oxide to the mixed aggregate for a second mixing to obtain a premix;

[0012] (3) adding a binder to the premix and performing a third mixing; adding a solvent and performing a fourth mixing to obtain a mixture;

[0013] (4) sealing the mixed material to obtain stale material;

[0014] (5) pressing the aged material into a shape and drying it to obtain a green body;

[0015] (6) Sintering the green body to obtain the sagger resistant to corrosion by lithium battery materials.

[0016] The present invention uses lithium silicon aluminum oxide and magnesium aluminum spinel, mullite and corundum as matrix materials, and utilizes lithium silicon aluminum oxide and Li in electrode materials to form a +The reaction inertia effectively improves the resistance of the sagger to lithium corrosion. At the same time, the addition of lithium silicon aluminum oxide avoids the reverse diffusion of foreign elements to the lithium battery material, preventing the contamination of the lithium battery material. In addition, the prepared sagger resistant to lithium battery material corrosion can also react with the active lithium component in the positive electrode material during service to form a stable LiAlO2 or LiAlSiO4 interface corrosion layer. This corrosion layer can effectively inhibit the chemical corrosion of the sagger by the highly active lithium component in the electrode material. In the present invention, the addition of lithium silicon aluminum oxide can also reduce the thermal expansion coefficient of the sagger, reduce the stress caused by thermal cycling, and improve the thermal shock resistance of the sagger.

[0017] The present invention first uses magnesia-alumina spinel aggregate, mullite aggregate and corundum aggregate to construct a discrete and uniformly distributed skeleton, and then uses magnesia-alumina spinel fine powder, mullite fine powder, corundum fine powder, zirconia, clay and lithium silicon aluminum oxide to fill the aggregate pores to construct a densified structure. At the same time, the high-temperature solid solution of lithium silicon aluminum oxide and magnesia-alumina spinel reduces the lowest eutectic point of the system, promotes the sintering degree of the system, and thereby reduces the apparent porosity of the material, effectively hindering the penetration and diffusion of lithium active components into the sagger under high-temperature environment.

[0018] The present invention utilizes a compression molding method to prepare a homogeneous sagger in one step, thereby ensuring the consistency of the overall performance of the sagger and also improving the yield rate of the sagger.

[0019] In the present invention, the types of adhesive and solvent are not specifically limited, and adhesives commonly used in the art are applicable to the technical solution of the present invention. For example, the adhesive may be dextrin, and the solvent may be water and / or ethanol.

[0020] Preferably, the mass ratio of the magnesia-alumina spinel aggregate, mullite aggregate and corundum aggregate in step (1) is 1:(1.5-5):(2-6).

[0021] Preferably, the mass ratio of the magnesium aluminum spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay, lithium silicon aluminum oxide in step (2) to the magnesium aluminum spinel aggregate in step (1) is (0.5-2):(2-5):(1.5-4):(0.5-2):(1.1-2):(0.1-2):1.

[0022] Preferably, the mass ratio of the binder in step (3) to the magnesia-alumina spinel aggregate in step (1) is (0.1-1):1.

[0023] Preferably, the mass ratio of the water in step (3) to the magnesia-alumina spinel aggregate in step (1) is (0.1-1):1.

[0024] In the present invention, the size of the aggregate is characterized by particle size, which indicates the range of particles between two particle sizes (particle diameters). For example, 2-0.5 mm indicates that the particle size is less than 2 mm and greater than 0.5 mm. For example, 1-0 mm indicates that the particle size is less than 1 mm and greater than 0 mm. In the present invention, "0 mm" specifically refers to particles with a particle size of less than 1 μm.

[0025] Preferably, the particle size of the magnesia-alumina spinel aggregate in step (1) is 1-0 mm.

[0026] Preferably, the particle size of the mullite aggregate in step (1) is 2-0.2 mm.

[0027] Preferably, the particle size of the corundum aggregate in step (1) is 1-0.5 mm.

[0028] Preferably, the material of the mullite aggregate in step (1) includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles.

[0029] Preferably, the mass ratio of the 2-1 mm mullite particles, the 1-0.2 mm mullite particles and the 1.5-0.2 mm mullite particles is 1:(1-10):(1-10).

[0030] Preferably, the material of the corundum aggregate in step (1) includes 1-0 mm corundum particles and 1-0.5 mm corundum particles.

[0031] Preferably, the mass ratio of the 1-0 mm corundum particles to the 1-0.5 mm corundum particles is 1:(0.5-2).

[0032] Preferably, the average particle size of the magnesia-alumina spinel fine powder, mullite fine powder and corundum fine powder in step (2) is 40 μm to 50 μm.

[0033] Preferably, the average particle size of the zirconium oxide in step (2) is 40 μm to 50 μm.

[0034] Preferably, the average particle size of the clay in step (2) is 40 μm to 50 μm.

[0035] Preferably, the average particle size of the lithium silicon aluminum oxide in step (2) is less than 74 μm.

[0036] Preferably, the mass percentage of CaO in the magnesia-alumina spinel aggregate in step (1) and the magnesia-alumina spinel fine powder in step (2) is independently less than 0.9%.

[0037] Preferably, the mass percentage of SiO2 in the magnesia-alumina spinel aggregate in step (1) and the magnesia-alumina spinel fine powder in step (2) is independently less than 0.6%.

[0038] Preferably, the mass percentage of TiO2 in the mullite aggregate in step (1) and the mullite fine powder in step (2) is independently less than 6%.

[0039] Preferably, the mass percentage of SiO2 in the corundum aggregate in step (1) and the corundum fine powder in step (2) is independently less than 0.2%.

[0040] Preferably, in the lithium silicon aluminum oxide in step (2), the molar ratio of Al to Si is 1:(0-2).

[0041] Preferably, the time for sealing the trapped material in step (4) is 12 hours to 24 hours.

[0042] Preferably, the pressing pressure in step (5) is 20 tons to 30 tons.

[0043] Preferably, the drying temperature in step (5) is 70°C to 90°C.

[0044] Preferably, the drying time in step (5) is 10 hours to 20 hours.

[0045] Preferably, the sintering temperature in step (6) is 1200°C to 1300°C.

[0046] Preferably, the sintering time in step (6) is 2 hours to 6 hours.

[0047] Preferably, the preparation method of the lithium silicon aluminum oxide in step (2) comprises: mixing a lithium source, a silicon source and an aluminum source, and calcining to obtain the lithium silicon aluminum oxide.

[0048] Preferably, the calcination temperature is 700°C to 1400°C.

[0049] Preferably, the calcination time is 2 hours to 6 hours.

[0050] In a second aspect, the present invention provides a sagger resistant to corrosion by lithium battery materials, wherein the sagger is prepared by the preparation method described in the first aspect.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) In the present invention, lithium silicon aluminum oxide and magnesium aluminum spinel, mullite and corundum are used as matrix materials. During the service process, the sagger can react with the active lithium component in the lithium battery material to form a stable LiAlO2 or LiAlSiO4 interface corrosion layer. The corrosion layer can effectively inhibit the chemical corrosion of the highly active lithium component in the electrode material to the sagger. + The reaction inertness of the sagger effectively improves the resistance of the sagger to lithium corrosion. At the same time, the addition of lithium silicon aluminum oxide avoids the reverse diffusion of heterogeneous elements into the lithium battery material and prevents the contamination of the lithium battery material.

[0053] (2) The preparation method provided by the present invention first uses magnesium aluminum spinel aggregate, mullite aggregate and corundum aggregate to construct a discrete uniformly distributed skeleton, and then uses magnesium aluminum spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay and lithium silicon aluminum oxide to fill the aggregate pores to construct a densified structure. At the same time, the high-temperature solid solution of lithium silicon aluminum oxide and magnesium aluminum spinel reduces the lowest eutectic point of the system, promotes the sintering degree of the system, and further reduces the apparent porosity of the material, effectively hindering the penetration and diffusion of lithium active components into the sagger under high temperature environment.

[0054] (3) In the present invention, the addition of lithium silicon aluminum oxide can reduce the thermal expansion coefficient of the sagger, reduce the stress caused by thermal cycling, and improve the thermal shock resistance of the sagger.

[0055] (4) The present invention utilizes a compression molding method to prepare a homogeneous sagger in one step, thereby ensuring the consistency of the overall performance of the sagger and also improving the yield rate of the sagger. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is an SEM image of the surface of the sagger resistant to lithium battery material corrosion prepared in Example 1.

[0057] Figure 2 This is a SEM image of the corroded surface of the sagger resistant to lithium battery material corrosion prepared in Example 1.

[0058] Figure 3 This is an SEM image of the surface of the sagger resistant to lithium battery material corrosion prepared in Example 2.

[0059] Figure 4 This is an SEM image of the surface of the sagger resistant to lithium battery material corrosion prepared in Example 3. DETAILED DESCRIPTION

[0060] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions.

[0062] In the description of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly indicate the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0063] In one embodiment, the present invention provides a method for preparing a sagger resistant to corrosion by lithium battery materials, the preparation method comprising:

[0064] (1) performing a first mixing of magnesia-alumina spinel aggregate, mullite aggregate, and corundum aggregate to obtain a mixed aggregate;

[0065] (2) adding magnesia-alumina spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay and lithium silicon aluminum oxide to the mixed aggregate for a second mixing to obtain a premix;

[0066] (3) adding a binder to the premix and performing a third mixing; adding a solvent and performing a fourth mixing to obtain a mixture;

[0067] (4) sealing the mixed material to obtain stale material;

[0068] (5) pressing the aged material into a shape and drying it to obtain a green body;

[0069] (6) Sintering the green body to obtain the sagger resistant to corrosion by lithium battery materials.

[0070] In the present invention, there is no specific limitation on the mixing method of all the above raw materials, as long as all the raw materials are uniformly mixed. For example, a blender, preferably a V-type blender, can be used.

[0071] In some embodiments, the mass ratio of the magnesia-alumina spinel aggregate, mullite aggregate and corundum aggregate in step (1) is 1:(1.5-5):(2-6), for example, it can be 1:1.5:2, 1:2:2.5, 1:2.5:3, 1:3:3.5, 1:3.5:4, 1:4:4.5, 1:4.5:5 or 1:5:6, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0072] In some embodiments, the mass ratio of the magnesium aluminum spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay, lithium silicon aluminum oxide in step (2) to the magnesium aluminum spinel aggregate in step (1) is (0.5-2):(2-5):(1.5-4):(0.5-2):(1.1-2):(0.1-2):1, for example, it can be 0.5:2:1.5:0.5:1.1:0.1:1, 0.8:2.5:2:0.7:1.2:0.5: 1, 1:3:2.5:0.9:1.4:0.7:1, 1.2:3.5:3:1.3:1.5:1:1, 1.4:4:3.3:1.5:1.6:1.3:1, 1.6:4.5:3.5:1.7:1.7:1.5:1, 1.8:4.8:3.8:1.9:1.8:1.7:1 or 2:5:4:2:2:2:1, including but not limited to the listed values, other values ​​not listed within the numerical range are also applicable.

[0073] In some embodiments, the mass ratio of the binder in step (3) to the magnesia-alumina spinel aggregate in step (1) is (0.1-1):1, for example, it can be 0.1:1, 0.3:1, 0.5:1, 0.7:1, 0.9:1 or 1:1, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0074] In some embodiments, the mass ratio of the water in step (3) to the magnesia-alumina spinel aggregate in step (1) is (0.1-1):1, for example, it can be 0.1:1, 0.3:1, 0.5:1, 0.7:1, 0.9:1 or 1:1, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0075] In some embodiments, the particle size of the magnesia-alumina spinel aggregate in step (1) is 1-0 mm.

[0076] In some embodiments, the particle size of the mullite aggregate in step (1) is 2-0.2 mm.

[0077] In some embodiments, the particle size of the corundum aggregate in step (1) is 1-0.5 mm.

[0078] In some embodiments, the material of the mullite aggregate in step (1) includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles.

[0079] In some embodiments, the mass ratio of the 2-1 mm mullite particles, the 1-0.2 mm mullite particles, and the 1.5-0.2 mm mullite particles is 1:(1-10):(1-10), for example, 1:1:1, 1:3:3, 1:5:5, 1:7:7, 1:9:8, or 1:10:10, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0080] In some embodiments, the material of the corundum aggregate in step (1) includes 1-0 mm corundum particles and 1-0.5 mm corundum particles.

[0081] In some embodiments, the mass ratio of the 1-0 mm corundum particles to the 1-0.5 mm corundum particles is 1:(0.5-2), for example, 1:0.5, 1:0.75, 1:1, 1:1.25, 1:1.5, 1:1.75 or 1:2, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0082] In some embodiments, the average particle size of the magnesia-alumina spinel fine powder, mullite fine powder and corundum fine powder in step (2) is 40 μm to 50 μm, for example, it can be 40 μm, 42 μm, 44 μm, 46 μm, 48 μm or 50 μm, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0083] In some embodiments, the average particle size of the zirconium oxide in step (2) is 40 μm to 50 μm, for example, 40 μm, 42 μm, 44 μm, 46 μm, 48 μm or 50 μm, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0084] In some embodiments, the average particle size of the clay in step (2) is 40 μm to 50 μm, for example, 40 μm, 42 μm, 44 μm, 46 μm, 48 μm or 50 μm, including but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0085] In some embodiments, the average particle size of the lithium silicon aluminum oxide in step (2) is less than 74 μm, for example, it can be 74 μm, 72 μm, 70 μm, 65 μm, 60 μm, 55 μm, 50 μm or 40 μm, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0086] In some embodiments, the mass percentage of CaO in the magnesium-aluminum spinel aggregate of step (1) and the magnesium-aluminum spinel fine powder of step (2) is independently less than 0.9%, for example, it can be 0.9%, 0.8%, 0.7%, 0.6% or 0.5%, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0087] In some embodiments, the mass percentage of SiO2 in the magnesium-aluminum spinel aggregate of step (1) and the magnesium-aluminum spinel fine powder of step (2) is independently less than 0.6%, for example, it can be 0.6%, 0.5%, 0.4%, 0.3%, 0.2% or 0.1%, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0088] In some embodiments, the mass percentage of TiO2 in the mullite aggregate of step (1) and the mullite fine powder of step (2) is independently less than 6%, for example, it can be 6%, 5%, 4%, 3%, 2%, 1% or 0.5%, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0089] In some embodiments, the mass percentage of SiO2 in the corundum aggregate of step (1) and the corundum fine powder of step (2) is independently less than 0.2%, for example, it can be 0.2%, 0.18%, 0.16%, 0.14%, 0.12% or 0.1%, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0090] In some embodiments, in the lithium silicon aluminum oxide described in step (2), the molar ratio of Al to Si is 1:(0-2), for example, it can be 1:0, 1:0.5, 1:1, 1:1.5 or 1:2, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0091] In some embodiments, the time for sealing the material in step (4) is 12h to 24h, for example, it can be 12h, 14h, 16h, 18h, 20h, 22h or 24h, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0092] In some embodiments, the pressing pressure in step (5) is 20 tons to 30 tons, for example, it can be 20 tons, 22 tons, 24 tons, 26 tons, 28 tons or 30 tons, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0093] In some embodiments, the drying temperature in step (5) is 70°C to 90°C, for example, 70°C, 75°C, 80°C, 85°C or 90°C, including but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0094] In some embodiments, the drying time in step (5) is 10 h to 20 h, for example, 10 h, 12 h, 14 h, 16 h, 18 h or 20 h, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0095] In some embodiments, the sintering temperature in step (6) is 1200°C to 1300°C, for example, it can be 1200°C, 1240°C, 1260°C, 1280°C or 1300°C, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0096] In some embodiments, the sintering time in step (6) is 2 hours to 6 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours or 6 hours, including but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0097] In some embodiments, the preparation method of the lithium silicon aluminum oxide in step (2) includes: mixing a lithium source, a silicon source and an aluminum source, and calcining to obtain the lithium silicon aluminum oxide.

[0098] In some embodiments, the lithium source includes any one or a combination of at least two of lithium hydroxide, lithium carbonate, lithium oxalate or lithium nitrate. Typical but non-limiting combinations include a combination of lithium hydroxide and lithium carbonate, a combination of lithium oxalate and lithium nitrate, or a combination of lithium hydroxide and lithium nitrate.

[0099] In some embodiments, the silicon source comprises silicon dioxide.

[0100] In some embodiments, the aluminum source comprises aluminum oxide.

[0101] In some embodiments, the calcination temperature is 700°C to 1400°C, for example, 700°C, 800°C, 900°C, 1000°C, 1100°C, 1200°C, 1300°C or 1400°C, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0102] In some embodiments, the calcination time is 2 h to 6 h, for example, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h or 6 h, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0103] In another specific embodiment, the present invention provides a sagger resistant to corrosion by lithium battery materials, wherein the sagger is prepared by the preparation method described in the first aspect.

[0104] Example 1

[0105] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials, comprising:

[0106] (1) Preparation of lithium silicon aluminum oxide: lithium carbonate, aluminum oxide and silicon dioxide were mixed in a Li:Al molar ratio of 1:1:1 and calcined at 700°C for 4h to prepare LiAlO2.

[0107] (2) 1-0 mm magnesia-alumina spinel aggregate, 2-0.2 mm mullite aggregate and 1-0.5 mm corundum aggregate are first mixed in a mass ratio of 1:1.5:2 to obtain a mixed aggregate; wherein the material of the mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles in a mass ratio of 1:1:2, and the material of the corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles in a mass ratio of 1:0.5; the mass ratio of CaO in the magnesia-alumina spinel aggregate is 0.8%, the mass ratio of SiO2 in the magnesia-alumina spinel aggregate is 0.6%, the mass ratio of TiO2 in the mullite aggregate is 4.5%, and the mass ratio of SiO2 in the corundum aggregate is 0.2%.

[0108] (3) Adding magnesium aluminum spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay and LiAlO2 in a mass ratio of 0.5:2:1.5:0.5:1.1:0.1:1 to the magnesium aluminum spinel aggregate in step (1) to perform a second mixing to obtain a premix; wherein the average particle size of the mullite fine powder is 40 μm, the average particle size of the corundum fine powder is 43 μm, and the average particle size of the zirconium oxide is 44 μm; the average particle size of the clay is 42 μm, the average particle size of the LiAlO2 is 74 μm, the mass percentage of CaO in the magnesium aluminum spinel fine powder is 0.9%, the mass percentage of SiO2 in the magnesium aluminum spinel fine powder is 0.5%, the mass percentage of TiO2 in the mullite fine powder is 6%, and the mass percentage of SiO2 in the corundum fine powder is 0.1%.

[0109] (4) adding dextrin at a mass ratio of 0.1:1 to the magnesia-alumina spinel aggregate in step (1) to the premix obtained in step (3), and performing a third mixing; then adding water at a mass ratio of 0.1:1 to the magnesia-alumina spinel aggregate in step (1), and performing a fourth mixing to obtain a mixture;

[0110] (5) sealing the mixture for 12 hours to obtain aged material;

[0111] (6) Pressing the aged material into a shape under a pressure of 20 tons, and drying at 70° C. for 10 hours to obtain a green body;

[0112] (7) Sintering the green body at 1200°C for 6 hours to obtain the sagger resistant to lithium battery corrosion. The morphology of the sagger surface is as follows: Figure 1 shown.

[0113] Example 2

[0114] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials, comprising:

[0115] (1) Preparation of lithium silicon aluminum oxide: lithium carbonate, aluminum oxide and silicon dioxide were mixed in a Li:Al:Si molar ratio of 1:1:1 and calcined at 1350°C for 3h to prepare LiAlSiO4.

[0116] (2) 1-0 mm magnesia-alumina spinel aggregate, 2-0.2 mm mullite aggregate and 1-0.5 mm corundum aggregate are first mixed in a mass ratio of 1:3:4 to obtain a mixed aggregate; wherein the material of the mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles in a mass ratio of 1:5:7, and the material of the corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles in a mass ratio of 1:1.5; the mass percentage of CaO in the magnesia-alumina spinel aggregate is 0.6%, the mass percentage of SiO2 in the magnesia-alumina spinel aggregate is 0.5%, the mass percentage of TiO2 in the mullite aggregate is 4%, and the mass percentage of SiO2 in the corundum aggregate is 0.15%.

[0117] (3) Adding magnesia-alumina spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay and LiAlSiO4 in a mass ratio of 1:3:3:1:1.5:1:1 to the magnesia-alumina spinel aggregate in step (1) to perform a second mixing to obtain a premix; wherein the average particle size of the mullite fine powder is 45 μm, the average particle size of the corundum fine powder is 44 μm, and the average particle size of the zirconium oxide is 43 μm; the average particle size of the clay is 47 μm, the average particle size of the LiAlSiO4 is 72 μm, the mass ratio of CaO in the magnesia-alumina spinel fine powder is 0.7%, the mass ratio of SiO2 in the magnesia-alumina spinel fine powder is 0.6%, the mass ratio of TiO2 in the mullite fine powder is 5%, and the mass ratio of SiO2 in the corundum fine powder is 0.15%.

[0118] (4) adding dextrin at a mass ratio of 0.5:1 to the magnesia-alumina spinel aggregate in step (1) to the premix obtained in step (3), and performing a third mixing; then adding water at a mass ratio of 0.6:1 to the magnesia-alumina spinel aggregate in step (1), and performing a fourth mixing to obtain a mixture;

[0119] (5) sealing the mixture for 18 hours to obtain aged material;

[0120] (6) Pressing the aged material into a shape under a pressure of 25 tons, and drying at 80° C. for 15 hours to obtain a green body;

[0121] (7) Sintering the green body at 1250°C for 4 hours to obtain the sagger resistant to lithium battery corrosion. The morphology of the sagger surface is as follows: Figure 3 shown.

[0122] Example 3

[0123] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials, comprising:

[0124] (1) Preparation of lithium silicon aluminum oxide: lithium carbonate, aluminum oxide and silicon dioxide were mixed in a Li:Al:Si molar ratio of 1:1:2 and calcined at 1400°C for 2h to prepare LiAlSi2O6.

[0125] (2) 1-0 mm magnesia-alumina spinel aggregate, 2-0.2 mm mullite aggregate and 1-0.5 mm corundum aggregate are first mixed in a mass ratio of 1:5:6 to obtain a mixed aggregate; wherein the material of the mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles in a mass ratio of 1:10:9, and the material of the corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles in a mass ratio of 1:2; the mass percentage of CaO in the magnesia-alumina spinel aggregate is 0.8%, the mass percentage of SiO2 in the magnesia-alumina spinel aggregate is 0.49%, the mass percentage of TiO2 in the mullite aggregate is 4.6%, and the mass percentage of SiO2 in the corundum aggregate is 0.2%.

[0126] (3) Adding magnesia-alumina spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay and LiAlSi2O6 in a mass ratio of 2:5:4:2:2:2:1 to the magnesia-alumina spinel aggregate in step (1) to perform a second mixing to obtain a premix; wherein the average particle size of the mullite fine powder is 48 μm, the average particle size of the corundum fine powder is 50 μm, and the average particle size of the zirconium oxide is 40 μm; the average particle size of the clay is 50 μm, the average particle size of the LiAlSi2O6 is 70 μm, the mass ratio of CaO in the magnesia-alumina spinel fine powder is 0.9%, the mass ratio of SiO2 in the magnesia-alumina spinel fine powder is 0.6%, the mass ratio of TiO2 in the mullite fine powder is 6%, and the mass ratio of SiO2 in the corundum fine powder is 0.2%.

[0127] (4) adding dextrin in a mass ratio of 1:1 to the magnesia-alumina spinel aggregate in step (1) to the premix obtained in step (3), and performing a third mixing; then adding water in a mass ratio of 1:1 to the magnesia-alumina spinel aggregate in step (1), and performing a fourth mixing to obtain a mixture;

[0128] (5) sealing the mixture for 24 hours to obtain aged material;

[0129] (6) Pressing the aged material into a shape under a pressure of 30 tons, and drying at 90° C. for 20 hours to obtain a green body;

[0130] (7) Sintering the green body at 1300°C for 2 hours to obtain the sagger resistant to lithium battery corrosion. The morphology of the sagger surface is as follows: Figure 4 shown.

[0131] Example 4

[0132] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials. Except that the temperature for calcining lithium carbonate, aluminum oxide and silicon dioxide to prepare LiAlSiO4 is 1500°C, the rest is the same as that of Example 2.

[0133] Example 5

[0134] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials. Except that the temperature for calcining lithium carbonate, aluminum oxide and silicon dioxide to prepare LiAlSiO4 is 1100°C, the rest is the same as that of Example 2.

[0135] Example 6

[0136] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials. Except that the temperature for calcining lithium carbonate, aluminum oxide and silicon dioxide to prepare LiAlSiO4 is 1000°C, the rest is the same as that of Example 2.

[0137] Example 7

[0138] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials. Except that the temperature for calcining lithium carbonate, aluminum oxide and silicon dioxide to prepare LiAlSiO4 is 1600°C, the rest is the same as that of Example 2.

[0139] Example 8

[0140] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials. Except that the mass ratio of LiAlSiO4 to the magnesium-aluminum spinel aggregate in step (1) is 0.05:1, the rest is the same as that in Example 2.

[0141] Example 9

[0142] This embodiment provides a method for preparing a sagger resistant to corrosion by lithium battery materials. Except that the mass ratio of LiAlSiO4 to the magnesium-aluminum spinel aggregate in step (1) is 2:1, the rest is the same as that in Example 2.

[0143] Comparative Example 1

[0144] This comparative example provides a method for preparing a sagger, which is the same as Example 1 except that LiAlSiO4 is not added.

[0145] Comparative Example 2

[0146] This comparative example provides a method for preparing a sagger, which is the same as Example 3 except that LiAlSiO4 is not added.

[0147] Performance testing:

[0148] The surface morphology of the saggers resistant to lithium battery corrosion prepared in Example 1, Example 2 and Example 3 was tested by SEM. The test results are shown in Table 1. Figure 1 、 Figure 3 and Figure 4 .

[0149] The sagger resistant to lithium battery corrosion prepared in Example 1 was used to prepare NCM811 positive electrode material. The erosion layer of the sagger resistant to lithium battery corrosion after service was subjected to SEM test. The test results are shown in Figure 2 .

[0150] According to the GB / T2997-2015 test standard, the apparent porosity and bulk density of the saggers prepared in all the above embodiments and comparative examples were tested. The test results are shown in Table 1.

[0151] According to the GB / T3001-2017 test standard, the flexural strength of the saggers prepared in all the above embodiments and comparative examples was tested. The test results are shown in Table 1.

[0152] According to the GB / T30873-2014 test standard, the thermal shock stability of the saggers prepared in all the above examples and comparative examples was tested. The test conditions were: the saggers were heated to 1100° C. and cooled with circulating air three times. The strength retention rate before and after the test was calculated. The test results are shown in Table 1.

[0153] Table 1

[0154] Apparent porosity / % <![CDATA[Volume density / g·cm -3 > Flexural strength / MPa Strength retention rate / % Example 1 17 2.75 25 81 Example 2 17.7 2.8 29 83 Example 3 17.5 2.68 22 74 Example 4 19 2.75 20 75 Example 5 20.5 2.6 19 74 Example 6 19 2.72 20 75 Example 7 17 2.8 21 76 Example 8 19.6 2.7 20 77 Example 9 18 2.8 22 76 Comparative Example 1 20 2.5 18 70 Comparative Example 2 26 2.6 15 65

[0155] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for preparing a sagger resistant to lithium battery corrosion, characterized in that: The preparation method comprises: (1) performing a first mixing of magnesia-alumina spinel aggregate, mullite aggregate, and corundum aggregate to obtain a mixed aggregate; (2) adding magnesia-alumina spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay and lithium silicon aluminum oxide to the mixed aggregate for a second mixing to obtain a premix; (3) adding a binder to the premix and performing a third mixing; adding a solvent and performing a fourth mixing to obtain a mixture; (4) sealing the mixed material to obtain stale material; (5) pressing the aged material into a shape and drying it to obtain a green body; (6) Sintering the green body to obtain the sagger resistant to corrosion by lithium battery materials.

2. The preparation method according to claim 1, wherein The mass ratio of the magnesia-alumina spinel aggregate, mullite aggregate and corundum aggregate in step (1) is 1:(1.5-5):(2-6); Preferably, the mass ratio of the magnesium aluminum spinel fine powder, mullite fine powder, corundum fine powder, zirconium oxide, clay, lithium silicon aluminum oxide in step (2) to the magnesium aluminum spinel aggregate in step (1) is (0.5-2):(2-5):(1.5-4):(0.5-2):(1.1-2):(0.1-2):1; Preferably, the mass ratio of the binder in step (3) to the magnesia-alumina spinel aggregate in step (1) is (0.1-1):1; Preferably, the mass ratio of the solvent in step (3) to the magnesium-aluminum spinel aggregate in step (1) is (0.1-1):

1.

3. The preparation method according to claim 1 or 2, wherein The particle size of the magnesia-alumina spinel aggregate in step (1) is 1-0 mm; Preferably, the particle size of the mullite aggregate in step (1) is 2-0.2 mm; Preferably, the particle size of the corundum aggregate in step (1) is 1-0.5 mm; Preferably, the material of the mullite aggregate in step (1) includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles; Preferably, the mass ratio of the 2-1 mm mullite particles, the 1-0.2 mm mullite particles and the 1.5-0.2 mm mullite particles is 1:(1-10):(1-10); Preferably, the material of the corundum aggregate in step (1) includes 1-0 mm corundum particles and 1-0.5 mm corundum particles; Preferably, the mass ratio of the 1-0 mm corundum particles to the 1-0.5 mm corundum particles is 1:(0.5-2).

4. The preparation method according to any one of claims 1 to 3, characterized in that The average particle size of the magnesia-alumina spinel fine powder, mullite fine powder and corundum fine powder in step (2) is 40 μm to 50 μm; Preferably, the average particle size of the zirconium oxide in step (2) is 40 μm to 50 μm; Preferably, the average particle size of the clay in step (2) is 40 μm to 50 μm; Preferably, the average particle size of the lithium silicon aluminum oxide in step (2) is less than 74 μm.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The mass percentage of CaO in the magnesia-alumina spinel aggregate of step (1) and the magnesia-alumina spinel fine powder of step (2) is independently less than 0.9%; Preferably, the mass percentage of SiO2 in the magnesia-alumina spinel aggregate in step (1) and the magnesia-alumina spinel fine powder in step (2) is independently less than 0.6%; Preferably, the mass percentage of TiO2 in the mullite aggregate in step (1) and the mullite fine powder in step (2) is independently less than 6%; Preferably, the mass percentage of SiO2 in the corundum aggregate of step (1) and the corundum fine powder of step (2) is independently less than 0.2%; Preferably, in the lithium silicon aluminum oxide in step (2), the molar ratio of Al to Si is 1:(0-2).

6. The preparation method according to any one of claims 1 to 5, characterized in that The time for sealing the trapped material in step (4) is 12 hours to 24 hours; Preferably, the pressure of the pressing molding in step (5) is 20 tons to 30 tons; Preferably, the drying temperature in step (5) is 70° C. to 90° C.; Preferably, the drying time in step (5) is 10 hours to 20 hours.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The sintering temperature in step (6) is 1200° C. to 1300° C.; Preferably, the sintering time in step (6) is 2 hours to 6 hours.

8. The preparation method according to any one of claims 1 to 7, characterized in that The preparation method of the lithium silicon aluminum oxide in step (2) comprises: A lithium source, a silicon source and an aluminum source are mixed and calcined to obtain the lithium silicon aluminum oxide.

9. The preparation method according to claim 8, wherein The calcination temperature is 700°C to 1400°C; Preferably, the calcination time is 2 hours to 6 hours.

10. A sagger resistant to corrosion by lithium battery materials, characterized in that: The sagger is prepared by the preparation method according to any one of claims 1 to 9.

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