CN114988870A - A kind of preparation method of zirconia fiber cotton - Google Patents

Abstract

The invention discloses a preparation method of zirconia fiber. Belongs to the field of new materials. The method comprises the steps of taking basic zirconium carbonate, glacial acetic acid, yttrium nitrate hexahydrate and other additives as main raw materials, dissolving the main raw materials in distilled water according to a certain proportion, and fully stirring the main raw materials at the temperature of 40-80 ℃ until the solution is colorless and uniform; concentrating the solution at 70-80 ℃ under reduced pressure to obtain a proper solution with certain viscosity, and adding solvents such as DMSO, NMP, DMF and DMAc to mix to prepare a precursor solution capable of electrostatic spinning; the precursor spinning solution is subjected to electrostatic spinning to obtain fibril, and then the zirconium oxide cellucotton is prepared through high-temperature heat treatment. The zirconia fiber has the diameter of 100-2000 nm, is continuous and good in flexibility, and the volume density range of cellucotton is 8mg/cm ³ ‑300mg/cm ³ Can be used in the field of heat insulation and preservation.

Description

A kind of preparation method of zirconia fiber cotton

technical field

The invention relates to the technical field of new materials, in particular to a preparation method of zirconia ceramic fibers.

Background technique

The low temperature performance of new energy vehicle power batteries seems to have determined the limitations of the sales area of electric vehicles, but with the support of national policies and the joint efforts of engineers, one of the methods to solve the low temperature performance of power batteries: thermal insulation design came into being, Common heat preservation functions include passive heat preservation, active heat preservation and charging heat preservation. Regardless of the thermal insulation scheme, the battery pack usually needs a thermal insulation buffer medium, generally using materials such as foamed silica gel, mica, and aerogel composite materials. However, due to the high density of mica, the thermal conductivity of foamed silica gel is difficult to meet more and more stringent requirements, and the fragile characteristics of aerogel materials limit its application.

To sum up, it is difficult for existing materials to provide complete thermal protection of batteries. Once problems such as thermal runaway of batteries occur, it is easy to cause accidents such as combustion or even explosion. Therefore, new materials that meet the requirements are urgently needed for battery protection.

SUMMARY OF THE INVENTION

The purpose of the preparation method of a zirconia fiber cotton of the present invention is to provide a new method for preparing a zirconia ceramic fiber cotton material with low thermal conductivity, so as to solve the increasingly strict use of thermal insulation and flame retardant materials in existing power batteries requested question.

In order to achieve the above purpose, the preparation method of a zirconia fiber cotton of the present invention is realized by a two-step technical solution. First, the first step is to configure a spinning precursor solution, and then use the spinning precursor solution to perform an electrospinning process to obtain the original solution. Fiber, fibril heat treatment to obtain zirconia ceramic fiber.

First, step 1 prepares the spinning precursor solution, which is prepared as follows:

The following raw materials are used in the present invention: basic zirconium carbonate, glacial acetic acid (acetic acid), yttrium nitrate, yttrium chloride, gadolinium nitrate, cerium nitrate, cerium chloride, aluminum chloride, aluminum nitrate, N,N-dimethylmethane Amide (DMF), N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), distilled water, etc.

Wherein basic zirconium carbonate is used as zirconium source; yttrium nitrate, yttrium chloride, gadolinium nitrate, cerium nitrate, cerium chloride, aluminum chloride, aluminum nitrate are used as stabilizers for zirconia fibers; N,N-dimethylformamide ( DMF), N,N-dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP), distilled water were used as solvents.

First, weigh basic zirconium carbonate, glacial acetic acid, stabilizer Add solvent and distilled water at 30～80℃ until the solution is colorless and homogeneous; then at 50～80℃, the solution is directly stirred and evaporated or concentrated under reduced pressure to a solution with a certain viscosity, and then add solvent to it and mix evenly The precursor solution b configured for electrospinning is used to prepare fibers by electrospinning. The stabilizer can be yttrium nitrate, yttrium chloride, gadolinium nitrate, cerium nitrate, cerium chloride, aluminum chloride, aluminum nitrate. Solvents can be added with N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), distilled water, etc. The proportion of addition is 0%-50% of the total mass ratio of the precursor solution b.

Then in step 2, using the spinning precursor solution b prepared in step 1 as a raw material, fibers are prepared by using an electrospinning method, and then the prepared fibrils are heat-treated to finally obtain zirconia ceramic fibers. as follows:

The obtained spinning precursor solution b was added to a syringe with a dispensing needle, and high-voltage electrospinning was carried out by high-voltage electrospinning. The range is 5-100kV, and the collection distance is between 5-50cm.

The prepared fibers are fibrils, and after heat treatment, zirconia ceramic fibers are obtained. The diameter of the prepared zirconia ceramic fibers ranges from 10 to 2000 nm, and the bulk density of the fiber wool ranges from 1 mg/cm ³ to 300 mg/cm ³ .

The preparation method of a kind of zirconia fiber cotton of the present invention has the following advantages:

The zirconia fiber cotton material prepared by the electrospinning technology combined with heat treatment in the invention has low thermal conductivity, and the cotton structure is formed by the accumulation of fibers to achieve thermal insulation effect.

The diameter range of the fiber made by the invention is controllable, and the density of the fiber cotton is adjustable.

The preparation method of the invention is simple and feasible, has excellent stability and low cost.

Description of drawings

Figure 1 is an SEM image of zirconia ceramic fibers. It can be seen from the image that the fibers are continuous and uniform, with a diameter of about 500 nm.

Figure 2 Digital photo of zirconia ceramic fiber cotton, combined with Figure 1, it can be seen that zirconia ceramic fibers are intertwined and stacked to form zirconia ceramic fiber cotton.

Detailed ways

The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

Example 1

(1) Preparation of yttrium zirconate precursor sol spinning solution:

Raw materials: basic zirconium carbonate, glacial acetic acid (acetic acid), yttrium nitrate, distilled water

Weigh 100g of basic zirconium carbonate, 100g of glacial acetic acid, 8g of yttrium nitrate, and 150g of distilled water, and stir at 60°C; when the solid is completely dissolved, the reaction solution is converted into a transparent solution, and concentrated under reduced pressure at 60°C until it is obtained. Colorless and transparent yttrium zirconate sol spinning solution; no spinning auxiliaries required for electrospinning are added.

(2) Electrospinning

Add the yttrium zirconate sol spinning solution into a syringe with a 23G dispensing needle, push the propelling pump at a rate of 3mL/h to squeeze out the solution in the syringe, and cover the receiving device with aluminum foil to collect fibers; at a temperature of 25°C, humidity is 50%, the voltage is 15kV, the receiving distance is 10cm, the spinning solution is ejected from the dispensing needle, and the yttrium zirconate precursor fiber is obtained.

(3) High temperature heat treatment

The fibrils obtained by electrospinning were placed in a program-controlled sintering furnace for medium and high temperature heat treatment. The heating rate was 1°C/min to 350°C, and the temperature was kept for 2h, the heating rate was 2°C/min to 600°C, and the temperature was kept for 2h, and the heating rate was 5°C/min to 800°C, and the temperature was kept for 3h. Zirconia fiber cotton was obtained. The diameter range of the prepared zirconia ceramic fiber is 100-1500nm, and the bulk density of the fiber cotton is in the range of 10mg/cm ³ -100mg/cm ³ .

Example 2

(1) Preparation of yttrium zirconate precursor sol spinning solution:

Raw materials: basic zirconium carbonate, glacial acetic acid (acetic acid), yttrium nitrate, distilled water, dimethyl sulfoxide (DMSO)

Weigh 100g of basic zirconium carbonate, 75g of glacial acetic acid, 8g of yttrium nitrate, and 1700g of distilled water, and stir under the condition of 60 ° C; when the solid is completely dissolved, the reaction solution is converted into a transparent solution, and concentrated under reduced pressure at 70 ° C until obtaining Colorless and transparent solution a, then add 10wt% DMSO, stir evenly to obtain electrospinning precursor solution b.

(2) Electrospinning

Add zirconium spinning solution b into a syringe with a 23G dispensing needle, push the propelling pump at a rate of 5mL/h to squeeze out the solution in the syringe, and cover the receiving device with aluminum foil to collect fibers; the voltage is 30kV, and the receiving distance is 10cm , the spinning solution is ejected from the dispensing needle to obtain the precursor fiber cotton.

(3) High temperature heat treatment

The fibrils prepared by electrospinning were put into a drying oven at 100°C for 24 hours, and then heat-treated at 800°C for 4 hours in a muffle furnace, and the temperature generation rate was controlled at 2°C/min. After heat treatment, zirconia fiber cotton is obtained. The diameter of the prepared zirconia ceramic fibers ranges from 20 to 1000 nm, and the bulk density of the fiber wool ranges from 10 mg/cm ³ to 100 mg/cm ³ .

Example 3

(1) Preparation of yttrium zirconate precursor sol spinning solution:

Raw materials: basic zirconium carbonate, glacial acetic acid (acetic acid), gadolinium nitrate, distilled water, N,N-dimethylacetamide (DMAc)

Take 100g of basic zirconium carbonate, 75g of glacial acetic acid, 6g of gadolinium nitrate, and 1700g of distilled water, and stir at 60 °C; when the solid is completely dissolved, the reaction solution is transformed into a transparent solution, and concentrated under reduced pressure at 70 °C until no color-transparent solution a, then add 5wt% DMAc, stir evenly to obtain electrospinning precursor solution b.

(2) Electrospinning

Add the zirconium spinning solution b into a syringe with a 25G dispensing needle, push the propelling pump at a rate of 5mL/h to squeeze out the solution in the syringe, and cover the receiving device with aluminum foil to collect fibers; the voltage is 25kV, and the receiving distance is 8cm , the spinning solution is ejected from the dispensing needle to obtain the precursor fiber cotton.

(3) High temperature heat treatment

The fibrils obtained by electrospinning were placed in a program-controlled sintering furnace for medium and high temperature heat treatment, the heating rate was 3 °C/min to 120 °C, and the temperature was kept for 1 h, and the heating rate was 1 °C/min to 200 °C, and the temperature was kept for 1 h. 1°C/min heating rate to 350°C, and holding for 2h, 2°C/min heating rate to 600°C, and holding for 2h, 5°C/min heating rate to 800°C, holding for 3h. Zirconia fiber cotton was obtained. The diameter range of the prepared zirconia ceramic fiber is 40-1200nm, and the bulk density of the fiber cotton is 1mg/cm ³ -100mg/cm ³

Although the present invention has been described in detail above with general description and specific embodiments, some modifications or improvements can be made on the basis of the present invention, which will be obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention fall within the scope of the claimed protection of the present invention.

Claims (5)

1. a zirconia fiber cotton material is characterized in that: The raw materials include: using basic zirconium carbonate as a zirconium source; glacial acetic acid (acetic acid) as a hydrolysis regulator; yttrium nitrate, yttrium chloride, gadolinium nitrate, cerium nitrate, cerium chloride, aluminum chloride, and aluminum nitrate as stabilizers; N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP), distilled water, etc. are used as solvents. 2. a preparation method of zirconia ceramic fiber, its characteristic process steps are as follows: Step 1: Prepare solution a with basic zirconium carbonate, acetic acid, stabilizer, and distilled water, and prepare solution a by vacuum distillation or heating evaporation; then add N,N-dimethylformamide (DMF), N,N-dimethicone Methylacetamide (DMAc), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), distilled water, etc. are used as solvents to configure spinning precursor solution b; Step 2: Using the spinning precursor solution b prepared in the previous step, fibers are prepared by using an electrospinning method, and the obtained fibrils are subjected to heat treatment at 600-1200° C. to obtain zirconia fibers. 3. As described in claim 1, 2, wherein the proportion of raw materials is as follows: basic zirconium carbonate: glacial acetic acid: distilled water: stabilizer=100: (30-120): (100-200): (0-20) The solution a is prepared in a mass ratio, and then a solvent is added to the solution a to prepare a spinning precursor solution b, and the addition amount of the solvent is 0wt%-50wt%. 4. According to claims 1, 2, and 3, the obtained spinning precursor solution b is prepared, and the fibers are prepared by an electrospinning process, and the fibrils are heat-treated at 600-1200° C. to obtain zirconia ceramic fibers. The process conditions of electrospinning, the single-needle injection flow rate is 0.01-20 mL/h, the voltage range is 5-100 kV, and the collection distance is between 5-50 cm. 5. According to claim 1, 2, 3, the spinning precursor solution obtained is configured to prepare fibers using an electrospinning method, and the obtained fibrils are subjected to heat treatment to obtain zirconia fiber cotton, which is a zirconia ceramic fiber , using the spinning precursor solution b as the raw material of the electrospinning preparation method, the diameter of the fibers prepared by the electrospinning method is 10-2000 nm, and the bulk density of the fiber cotton is in the range of 1 mg/cm ³ -300 mg/cm ³ .

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