Nanometer barium titanate for MLCC and preparation method thereof

Abstract

The application relates to nano-barium titanate for MLCC and a preparation method thereof. The technical scheme is as follows: a titanyl sulfate solution, tetrabutyl titanate and potassium dihydrogen phosphate solution are mixed, urea is added under the condition of magnetic stirring, the pH value is adjusted to 8.5-10.5, the titanium oxide slurry is continuously stirred at 80-95 DEG C for 2-3 hours, the titanium oxide slurry is spray-dried, and the titanium oxide powder is obtained; the titanium oxide powder, barium oxide and hydroxide are mixed, pure water and ethylene glycol are added, and the mixture is uniformly mixed to obtain a precursor suspension; the precursor suspension is moved to a polytetrafluoroethylene reaction kettle, heated in a microwave device, kept warm, naturally cooled, washed, filtered and dried, and the nano-barium titanate for MLCC is prepared. The application has the characteristics of small energy consumption, low production cost and short production cycle, the prepared nano-barium titanate powder for MLCC has high purity, small particle size, good dispersity and high tetragonal property, and can be directly applied to chip multilayer ceramic capacitors.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electronic material applications. Specifically relates to a kind of nano barium titanate for MLCC and its preparation method. BACKGROUND

[0002] BaTiO3(BT) perovskite structure material is an important dielectric material, due to its high dielectric constant and excellent ferroelectric properties, widely used in electronic industry, especially in the field of MLCC (“MLCC” is the English abbreviation of chip multilayer ceramic capacitor). Tetragonal phase BaTiO3 powder is the key raw material of current large-capacity ultra-thin MLCC device, and with the miniaturization of MLCC, the size will be further reduced, so it is concerned by those skilled in the art to prepare a kind of nano barium titanate for MLCC.

[0003] Sun Jian (Sun Jian. Preparation method of barium titanate powder with high crystallinity and uniform grain size [J]. Scientific and technological innovation, 2021 (17) ∶ 31-32.) adopts solid phase method, combined with two-step dispersion process and two-step calcination process to prepare tetragonal phase barium titanate powder with high crystallinity and uniform grain size, but the experimental process is complicated, secondary ball milling leads to easy introduction of impurities and high energy consumption.

[0004] The patent technology “a method for preparing barium titanate powder by solid phase synthesis” (CN113353974A) uses improved solid phase synthesis method, uses rotary furnace low-high temperature two-stage calcination method to obtain barium titanate powder with high tetragonality and high sintering activity, but the particle size of barium titanate is large, and the equipment investment of this method is large, the cost is high.

[0005] The patent technology “barium oxalate titanate, its manufacturing method and the manufacturing method of barium titanate” (CN115916792A) adopts oxalate method to obtain barium titanate with small particle size and high crystallinity, but the production cycle of this method is long, and the dispersion of barium titanate powder is poor, and the agglomeration phenomenon is serious, which affects the use. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art, and aims to provide a preparation method of nano barium titanate for MLCC with small energy consumption, low production cost and short production cycle. The nano barium titanate powder for MLCC prepared by the method has high purity, small particle size, good dispersion and high tetragonality, and can be directly applied to chip multilayer ceramic capacitors.

[0007] To achieve the above purpose, the specific technical solutions adopted by the present application are as follows:

[0008] Step one, according to the mass ratio of tetrabutyl titanate: titanyl sulfate solution is 1:10-30, the ingredients are mixed, and the mixture A is obtained; then according to the mass ratio of the mixture A: potassium dihydrogen phosphate solution is 1:0.5-0.6, the potassium dihydrogen phosphate solution is added to the mixture A, mixed, and the mixture B is obtained.

[0009] Step two, under the condition of magnetic stirring, urea solution is added to the mixture B, the pH is adjusted to 8.5-10.5, and the mixture C is obtained; the mixture C is continuously stirred at 80-95℃ for 2-3h, and the titanium oxide slurry is obtained, and then the titanium oxide slurry is spray dried at 230-260℃, and the titanium oxide powder is obtained.

[0010] Step three, according to the molar ratio of the titanium oxide powder: barium oxide is 1:1-1.05, the ingredients are mixed, and the mixture D is obtained; according to the molar ratio of sodium hydroxide: potassium hydroxide is 1:1, the ingredients are mixed, and the mixture E is obtained; according to the mass ratio of the mixture D: the mixture E is 1:1-3, the mixture F is obtained; then according to the mass ratio of the mixture F: ethylene glycol: deionized water is 1:1:1-5, ethylene glycol and deionized water are added to the mixture F, and the precursor suspension is obtained.

[0011] Step four, the precursor suspension is moved to a polytetrafluoroethylene reaction kettle, and then the polytetrafluoroethylene reaction kettle is placed in a microwave device and heated to 200-280℃ for 25-45min; then the precursor suspension after microwave heating is washed with deionized water for 3-5 times, and the filter cake is obtained after each washing and filtration; the filter cake is dried at 70-80℃ for 8-12h, and the nano barium titanate for MLCC is obtained.

[0012] The c / a of the nano barium titanate for MLCC is 1:1.094-1.011, and the specific surface area of the nano barium titanate for MLCC is >30m 2 / g.

[0013] The purity of the tetrabutyl titanate is more than 98%.

[0014] The purity of the titanyl sulfate solution is 93-99.95%.

[0015] The concentration of the potassium dihydrogen phosphate solution is 0.1-0.25wt%, and the potassium dihydrogen phosphate solution is a mixed solution of potassium dihydrogen phosphate and deionized water; wherein: the purity of the potassium dihydrogen phosphate particles is more than 99.95%.

[0016] The concentration of the urea solution is 40-60%.

[0017] The purity of the barium oxide particles is more than 99.9%.

[0018] The purity of the sodium hydroxide particles is 99.9% or more.

[0019] The purity of the potassium hydroxide particles is 99.9% or more.

[0020] The purity of the ethylene glycol is 99.9% or more.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] The present application uses titanyl sulfate solution and tetrabutyl titanate as the titanium source to prepare anatase titanium oxide powder with large specific surface area and high reactivity under normal pressure and low temperature. Then, the titanium oxide powder is mixed with barium oxide, and then hydroxide, pure water and ethylene glycol are added to obtain a precursor suspension. Finally, the precursor suspension is subjected to microwave hydrothermal treatment to obtain nano barium titanate for MLCC at low temperature. Therefore, the present application has the advantages of low energy consumption, low raw material cost and short production cycle.

[0023] In the process of preparing titanium oxide, the present application uses spray drying technology to obtain anatase titanium oxide powder at low temperature, which effectively ensures the reactivity of titanium oxide by avoiding the agglomeration of titanium oxide powder. In the process of synthesizing nano barium titanate for MLCC, the microwave hydrothermal treatment technology is used. Since a series of reactions are completed in a liquid medium, on the one hand, the mixing of barium ions and titanium ions is more uniform, and the generated barium titanate is uniformly dispersed in the medium. On the other hand, the use of microwave energy accelerates the reaction speed. The medium rotates at high speed under the action of the microwave field, and the reactants are uniformly heated in a short time, greatly eliminating the temperature gradient. The barium titanate is nucleated at a relatively low temperature, avoiding the shortcomings of poor crystallinity and long reaction time of the existing hydrothermal reaction. At the same time, under the combined action of microwave energy and pressure, the barium titanate crystal is more likely to undergo lattice distortion, and high tetragonality barium titanate can be obtained at a relatively low temperature. The present application has the advantages of low synthesis temperature, slow growth of barium titanate crystal, and small particle size of tetragonal barium titanate with high sintering activity.

[0024] The nano barium titanate for MLCC prepared by the present application has the following characteristics: high tetragonality (c / a is 1.094-1.011); and high sintering activity (specific surface area > 30 m 2 / g).

[0025] Therefore, the present application has the advantages of low energy consumption, low production cost and short production cycle. The nano barium titanate powder prepared by the method has high purity, small particle size, good dispersibility and high tetragonality, and can be directly applied to chip multilayer ceramic capacitors. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The XRD pattern of the nano barium titanate for MLCC prepared by the present application;

[0027] Figure 2 For Figure 1 SEM image of nano-barium titanate for MLCC. DETAILED DESCRIPTION

[0028] The application will be further described in conjunction with the drawings and specific embodiments, which are not intended to limit the scope of protection.

[0029] Nano-barium titanate for MLCC and a preparation method thereof. The steps of the preparation method described in the specific embodiment are as follows:

[0030] Step one, ingredients are prepared according to the mass ratio of tetrabutyl titanate to titania solution of 1:10-30, mixed, and mixed material A is obtained; then potassium dihydrogen phosphate solution is added to the mixed material A according to the mass ratio of the mixed material A to the potassium dihydrogen phosphate solution of 1:0.5-0.6, mixed, and mixed material B is obtained.

[0031] Step two, under the condition of magnetic stirring, urea solution is added to the mixed material B, and the pH is adjusted to 8.5-10.5, and mixed material C is obtained; the mixed material C is continuously stirred at 80-95℃ for 2-3h, and titania slurry is obtained, and then the titania slurry is spray dried at 230-260℃, and titania powder is obtained.

[0032] Step three, ingredients are prepared according to the molar ratio of the titania powder to barium oxide of 1:1-1.05, mixed, and mixed material D is obtained; ingredients are prepared according to the molar ratio of sodium hydroxide to potassium hydroxide of 1:1, mixed, and mixed material E is obtained; ingredients are prepared according to the mass ratio of mixed material D to mixed material E of 1:1-3, and mixed material F is obtained; then glycol and deionized water are added to the mixed material F according to the mass ratio of the mixed material F to glycol to deionized water of 1:1:1-5, and mixed uniformly, and precursor suspension is obtained.

[0033] Step four, the precursor suspension is moved into a polytetrafluoroethylene reaction kettle, and then the polytetrafluoroethylene reaction kettle is placed in a microwave device, heated to 200-280℃, and kept for 25-45min; then the precursor suspension after microwave heating is washed with deionized water for 3-5 times, and the filter cake is obtained after each washing and filtration; the filter cake is dried at 70-80℃ for 8-12h, and nano-barium titanate for MLCC is obtained.

[0034] The c / a of the nano-barium titanate for MLCC is 1:1.094-1.011, and the specific surface area of the nano-barium titanate for MLCC is >30m 2 / g.

[0035] The purity of the tetrabutyl titanate is more than 98%.

[0036] The purity of the titanyl sulfate solution is 93-99.95%.

[0037] The concentration of the potassium dihydrogen phosphate solution is 0.1-0.25wt%, and the potassium dihydrogen phosphate solution is a mixed solution of potassium dihydrogen phosphate and deionized water; wherein the purity of the potassium dihydrogen phosphate particles is above 99.95%.

[0038] The concentration of the urea solution is 40-60%.

[0039] The purity of the barium oxide particles is above 99.9%.

[0040] The purity of the sodium hydroxide particles is above 99.9%.

[0041] The purity of the potassium hydroxide particles is above 99.9%.

[0042] The purity of the ethylene glycol is above 99.9%.

[0043] Example 1

[0044] A nano-barium titanate for MLCC and a preparation method thereof. The preparation method of the present embodiment comprises the following steps:

[0045] Step one, ingredients are prepared according to the mass ratio of tetrabutyl titanate to titanyl sulfate solution as 1:10, and mixed to obtain a mixture A; then, the mixture A is added with a potassium dihydrogen phosphate solution according to the mass ratio of the mixture A to the potassium dihydrogen phosphate solution as 1:0.5, and mixed to obtain a mixture B.

[0046] Step two, under the condition of magnetic stirring, the mixture B is added with a urea solution to adjust the pH to 8.5 to obtain a mixture C; the mixture C is continuously stirred at 80℃ for 2h to obtain a titanium oxide slurry, and then the titanium oxide slurry is spray dried at 230℃ to obtain a titanium oxide powder.

[0047] Step three, ingredients are prepared according to the molar ratio of the titanium oxide powder to barium oxide as 1:1, and mixed to obtain a mixture D; ingredients are prepared according to the molar ratio of sodium hydroxide to potassium hydroxide as 1:1, and mixed to obtain a mixture E; ingredients are prepared according to the mass ratio of the mixture D to the mixture E as 1:1 to obtain a mixture F; then, the mixture F is added with ethylene glycol and deionized water according to the mass ratio of the mixture F to ethylene glycol to deionized water as 1:1:1, and mixed uniformly to obtain a precursor suspension.

[0048] Step four, the precursor suspension is moved to a polytetrafluoroethylene reactor, the polytetrafluoroethylene reactor is placed in a microwave device, heated to 200℃, and kept for 25 min; then the precursor suspension after microwave heating is washed with deionized water for 3 times, and after each washing, it is suction filtered to obtain a filter cake; the filter cake is dried at 70℃ for 8h to obtain the nano-barium titanate for MLCC.

[0049] The c / a of the nano-barium titanate for MLCC is 1:1.094, and the specific surface area of the nano-barium titanate for MLCC is 38.72m 2 / g.

[0050] The purity of the tetrabutyl titanate is 98.1%.

[0051] The purity of the titanyl sulfate solution is 93%.

[0052] The concentration of the potassium dihydrogen phosphate solution is 0.1wt%, and the potassium dihydrogen phosphate solution is a mixed solution of potassium dihydrogen phosphate and deionized water; wherein: the purity of the potassium dihydrogen phosphate particles is 99.96%.

[0053] The concentration of the urea solution is 40%.

[0054] The purity of the barium oxide particles is 99.91%.

[0055] The purity of the sodium hydroxide particles is 99.91%.

[0056] The purity of the potassium hydroxide particles is 99.91%.

[0057] The purity of the ethylene glycol is 99.91%.

[0058] Example 2

[0059] A nano-barium titanate for MLCC and a preparation method thereof. The preparation method of the present embodiment comprises the following steps:

[0060] Step one, ingredients are prepared according to the mass ratio of tetrabutyl titanate to titanyl sulfate solution as 1:20, mixed to obtain a mixed material A; then the mixed material A is added with a potassium dihydrogen phosphate solution according to the mass ratio of the mixed material A to the potassium dihydrogen phosphate solution as 1:0.53, mixed to obtain a mixed material B.

[0061] Step two, under the condition of magnetic stirring, the mixed material B is added with a urea solution, and the pH is adjusted to 9 to obtain a mixed material C; the mixed material C is continuously stirred at 90℃ for 2.5h to obtain a titanium oxide slurry, and then the titanium oxide slurry is spray dried at 240℃ to obtain a titanium oxide powder.

[0062] Step three, according to the molar ratio of titanium oxide powder: barium oxide is 1:1.01, the mixture is obtained by mixing the mixture D; according to the molar ratio of sodium hydroxide: potassium hydroxide is 1:1, the mixture is obtained by mixing, the mixture E; according to the mass ratio of mixture D: mixture E is 1:2, the mixture F is obtained; again according to the mass ratio of the mixture F: ethylene glycol: deionized water is 1:1:2, ethylene glycol and deionized water are added to the mixture F, and the mixture is uniformly mixed to obtain a precursor suspension.

[0063] Step four, the precursor suspension is moved to the polytetrafluoroethylene reactor, and the polytetrafluoroethylene reactor is placed in the microwave device, heated to 240℃, and kept for 30min; then the precursor suspension after microwave heating is washed with deionized water 4 times, and the filter cake is obtained after each washing by suction filtration; the filter cake is dried at 75℃ for 9h to obtain the nano barium titanate for MLCC.

[0064] The c / a of the nano barium titanate for MLCC is 1:1.097, and the specific surface area of the nano barium titanate for MLCC is 37.53m 2 / g.

[0065] The purity of the tetrabutyl titanate is 98.2%.

[0066] The purity of the titanyl sulfate solution is 95%.

[0067] The concentration of the potassium dihydrogen phosphate solution is 0.15wt%, and the potassium dihydrogen phosphate solution is a mixed solution of potassium dihydrogen phosphate and deionized water; wherein: the purity of the potassium dihydrogen phosphate particles is 99.97%.

[0068] The concentration of the urea solution is 45%.

[0069] The purity of the barium oxide particles is 99.92%.

[0070] The purity of the sodium hydroxide particles is 99.92%.

[0071] The purity of the potassium hydroxide particles is 99.92%.

[0072] The purity of the ethylene glycol is 99.92%.

[0073] Example 3

[0074] A nano barium titanate for MLCC and a preparation method thereof. The steps of the preparation method in this embodiment are:

[0075] Step one, according to the mass ratio of tetrabutyl titanate: titanyl sulfate solution is 1:25, dosing, mixing, namely the mixture A; again according to the mass ratio of the mixture A: potassium dihydrogen phosphate solution is 1:0.55, potassium dihydrogen phosphate solution is added to the mixture A, mixing, to get the mixture B.

[0076] Step two, under the condition of magnetic stirring, urea solution is added to the mixture B, adjust the pH to 10, to get the mixture C; the mixture C is continuously stirred at 95℃ for 2.5h, to get the titanium oxide slurry, then the titanium oxide slurry is spray dried at 250℃, to get the titanium oxide powder.

[0077] Step three, according to the molar ratio of the titanium oxide powder: barium oxide is 1:1.03, dosing, mixing, to get the mixture D; according to the molar ratio of sodium hydroxide: potassium hydroxide is 1:1, dosing, mixing, to get the mixture E; according to the mass ratio of mixture D: mixture E is 1:3, to get the mixture F; again according to the mass ratio of the mixture F: ethylene glycol: deionized water is 1:1:4, ethylene glycol and deionized water are added to the mixture F, mixing uniformly, to get the precursor suspension.

[0078] Step four, the precursor suspension is moved to the polytetrafluoroethylene reactor, then the polytetrafluoroethylene reactor is placed in the microwave equipment, heated to 260℃, and kept for 35min; then the precursor suspension after microwave heating is washed with deionized water for 4 times, and the filter cake is obtained after each washing by suction filtration; the filter cake is dried at 78℃ for 10h, to get the nano barium titanate for MLCC.

[0079] The c / a of the nano barium titanate for MLCC is 1:1.099, and the specific surface area of the nano barium titanate for MLCC is 35.45m 2 / g.

[0080] The purity of the tetrabutyl titanate is 98.3%.

[0081] The purity of the titanyl sulfate solution is 97%.

[0082] The concentration of the potassium dihydrogen phosphate solution is 0.2wt%, and the potassium dihydrogen phosphate solution is a mixed solution of potassium dihydrogen phosphate and deionized water; wherein: the purity of the potassium dihydrogen phosphate particles is 99.98%.

[0083] The concentration of the urea solution is 50%.

[0084] The purity of the barium oxide particles is 99.93%.

[0085] The purity of the sodium hydroxide particles is 99.93%.

[0086] The purity of the potassium hydroxide particles is 99.93%.

[0087] The purity of the ethylene glycol is 99.93%.

[0088] Example 4

[0089] A nano-barium titanate for MLCC and a preparation method thereof. The preparation method of the present embodiment comprises the following steps:

[0090] Step one, ingredients are prepared according to the mass ratio of tetrabutyl titanate to titania sulfate solution as 1:30, and mixed to obtain a mixture A; then, potassium dihydrogen phosphate solution is added to the mixture A according to the mass ratio of the mixture A to the potassium dihydrogen phosphate solution as 1:0.6, and mixed to obtain a mixture B.

[0091] Step two, under the condition of magnetic stirring, urea solution is added to the mixture B to adjust the pH to 10.5 to obtain a mixture C; the mixture C is continuously stirred at 95℃ for 3h to obtain a titanium oxide slurry, and then the titanium oxide slurry is spray dried at 260℃ to obtain a titanium oxide powder.

[0092] Step three, ingredients are prepared according to the molar ratio of the titanium oxide powder to barium oxide as 1:1.05, and mixed to obtain a mixture D; ingredients are prepared according to the molar ratio of sodium hydroxide to potassium hydroxide as 1:1, and mixed to obtain a mixture E; ingredients are prepared according to the mass ratio of the mixture D to the mixture E as 1:3 to obtain a mixture F; then, ethylene glycol and deionized water are added to the mixture F according to the mass ratio of the mixture F to ethylene glycol to deionized water as 1:1:5, and mixed uniformly to obtain a precursor suspension.

[0093] Step four, the precursor suspension is moved into a polytetrafluoroethylene reaction kettle, and then the polytetrafluoroethylene reaction kettle is placed in a microwave device and heated to 280℃ for 45min; then, the precursor suspension after microwave heating is washed with deionized water for 5 times, and a filter cake is obtained after each washing by suction filtration; the filter cake is dried at 80℃ for 12h to obtain a nano-barium titanate for MLCC.

[0094] The c / a of the nano-barium titanate for MLCC is 1:1.011, and the specific surface area of the nano-barium titanate for MLCC is 30.19m 2 / g.

[0095] The purity of the tetrabutyl titanate is 98.4%.

[0096] The purity of the titania sulfate solution is 99%.

[0097] The concentration of the potassium dihydrogen phosphate solution is 0.25wt%, and the potassium dihydrogen phosphate solution is a mixed solution of potassium dihydrogen phosphate and deionized water; wherein the purity of the potassium dihydrogen phosphate particles is 99.96%.

[0098] The concentration of the urea solution is 60%.

[0099] The purity of the barium oxide particles is 99.94%.

[0100] The purity of the sodium hydroxide particles is 99.94%.

[0101] The purity of the potassium hydroxide particles is 99.94%.

[0102] The purity of the ethylene glycol is 99.94%.

[0103] The present embodiment has the following positive effects compared with the prior art:

[0104] The present embodiment uses titania sulfate solution and tetrabutyl titanate as the titanium source to prepare anatase titanium oxide powder with large specific surface area and high reactivity under normal pressure and low temperature; then the titanium oxide powder is mixed with barium oxide, and then hydroxide, pure water and ethylene glycol are added to obtain a precursor suspension; finally, the precursor suspension is subjected to microwave hydrothermal treatment to obtain nano barium titanate for MLCC at low temperature. Therefore, the present application has the advantages of low energy consumption, low raw material cost and short production cycle.

[0105] In the process of preparing titanium oxide, the present embodiment uses spray drying technology to obtain anatase titanium oxide powder at a lower temperature, while avoiding the agglomeration of titanium oxide powder and effectively ensuring the reactivity of titanium oxide; in the process of synthesizing nano barium titanate for MLCC, microwave hydrothermal treatment technology is used, and since a series of reactions are completed in a liquid medium, on the one hand, the mixing of barium ions and titanium ions is more uniform, and the generated barium titanate is uniformly dispersed in the medium; on the other hand, the use of microwave energy accelerates the reaction speed, and the medium rotates at high speed under the action of the microwave field, and the reactants are uniformly heated in a short time, greatly eliminating the temperature gradient, and making the barium titanate nucleate at a lower temperature, avoiding the shortcomings of poor crystallinity and long reaction time of the existing hydrothermal reaction; at the same time, under the joint action of microwave energy and pressure, the barium titanate crystal is more likely to undergo lattice distortion, and high tetragonality barium titanate can be obtained at a lower temperature. The present embodiment has the advantages of low synthesis temperature, slow growth of barium titanate crystal grains, and small particle size and high sintering activity of the obtained tetragonal barium titanate.

[0106] The nano barium titanate for MLCC prepared by the present embodiment is shown in the accompanying drawings: Figure 1 is the XRD pattern of the nano barium titanate for MLCC prepared in Example 1; Figure 2 is Figure 1SEM image of the nano-barium titanate for MLCC shown. From Figure 1 It can be seen that the prepared nano-barium titanate for MLCC is pure tetragonal phase, and no other impurity phase, indicating that the prepared nano-barium titanate for MLCC has high purity and good crystallinity; from Figure 2 It can be seen that the prepared nano-barium titanate for MLCC has a tetragonal morphology, small grain size and uniform distribution.

[0107] The nano-barium titanate for MLCC prepared in the embodiment is detected: high tetragonality (c / a is 1.094-1.011); high sintering activity (specific surface area > 30 m 2 / g).

[0108] The present application has the characteristics of low synthesis temperature, low production cost and short preparation time; the method can prepare tetragonal phase nano-barium titanate powder with high purity, small particle size, good dispersibility and high sintering activity.

Claims

1. A method for preparing nano-barium titanate for MLCC, characterized in that, The preparation method comprises the following steps: Step one, ingredients are prepared according to the mass ratio of tetrabutyl titanate to titanyl sulfate solution of 1:10-30, mixed, and a mixture A is obtained; then, potassium dihydrogen phosphate solution is added to the mixture A according to the mass ratio of the mixture A to the potassium dihydrogen phosphate solution of 1:0.5-0.6, mixed, and a mixture B is obtained; Step two, under the condition of magnetic stirring, urea solution is added to the mixture B, the pH is adjusted to 8.5-10.5, a mixture C is obtained; the mixture C is continuously stirred at 80-95°C for 2-3h, a titanium oxide slurry is obtained, and then the titanium oxide slurry is spray dried at 230-260°C, and a titanium oxide powder is obtained; Step three, ingredients are prepared according to the molar ratio of the titanium oxide powder to barium oxide particles of 1:1-1.05, mixed, and a mixture D is obtained; ingredients are prepared according to the molar ratio of sodium hydroxide particles to potassium hydroxide particles of 1:1, mixed, and a mixture E is obtained; ingredients are prepared according to the mass ratio of the mixture D to the mixture E of 1:1-3, and a mixture F is obtained; then, glycol and deionized water are added to the mixture F according to the mass ratio of the mixture F to the glycol to the deionized water of 1:1:1-5, mixed uniformly, and a precursor suspension is obtained; Step four, the precursor suspension is moved into a polytetrafluoroethylene reaction kettle, the polytetrafluoroethylene reaction kettle is placed in a microwave device, heated to 200-280°C, and kept warm for 25-45min; then, the precursor suspension after microwave heating is washed with deionized water for 3-5 times, and a filter cake is obtained after each washing and suction filtration; the filter cake is dried at 70-80°C for 8-12h, and a nano barium titanate for MLCC is obtained. The c / a of the nano-barium titanate for the MLCC is 1:1.094-1.011, and the specific surface area of the nano-barium titanate for the MLCC is >30 m 2 / g.

2. The method of claim 1, wherein the nano-barium titanate is prepared by the steps of: preparing a barium titanate precursor solution by mixing barium chloride, titanium dioxide, and a solvent; and preparing the nano-barium titanate by adding an alkali solution to the barium titanate precursor solution. The purity of the tetrabutyl titanate is more than 98%.

3. The method of claim 1, wherein the nano-barium titanate is prepared by the steps of: preparing a solution of barium titanate by mixing barium hydroxide and titanium dioxide; and adding a dispersant to the solution of barium titanate. The purity of the titanyl sulfate solution is 93-99.95%.

4. The method for preparing nano-barium titanate for MLCCs according to claim 1, characterized in that... The concentration of the potassium dihydrogen phosphate solution is 0.1-0.25wt%, and the potassium dihydrogen phosphate solution is a mixed solution of potassium dihydrogen phosphate and deionized water; wherein the purity of potassium dihydrogen phosphate particles is more than 99.95%.

5. The method of claim 1, wherein the nano-barium titanate is prepared by the steps of: preparing a solution of barium titanate by mixing barium hydroxide and titanium dioxide; and adding a dispersant to the solution of barium titanate. The concentration of the urea solution is 40-60%.

6. The method for preparing nano-barium titanate for MLCCs according to claim 1, characterized in that, The purity of the barium oxide particles is more than 99.9%.

7. The method for preparing nano-barium titanate for MLCCs according to claim 1, characterized in that, The purity of the sodium hydroxide particles is more than 99.9%.

8. The method for preparing nano-barium titanate for MLCCs according to claim 1, characterized in that, The purity of the potassium hydroxide particles is more than 99.9%.

9. The method for preparing nano-barium titanate for MLCCs according to claim 1, characterized in that, The purity of the glycol is more than 99.9%.

10. A nano-barium titanate for an MLCC, characterized by The nano barium titanate for MLCC is prepared according to the preparation method of the nano barium titanate for MLCC in any one of claims 1-9.

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