A method for preparing a defect-modulated barium titanate composite

Abstract

The present application belongs to the technical field of barium titanate preparation, and particularly relates to a preparation method of defect-regulated barium titanate composite material, which comprises the following preparation steps: S1: a proper amount of barium carbonate, titanium dioxide, nickel oxide and a dopant mixed powder are added into a ball mill tank for ball milling to obtain initial barium titanate composite particles; S2: the initial barium titanate composite particles obtained in step S1 are dispersed in an aqueous solution of a growth inhibitor to react to form modified barium titanate composite powder; S3: the barium titanate composite powder obtained in step S2 is mixed with a binder polyvinyl butyral, and then is pressed into a green body, cold isostatic pressing is performed, and then sintering is carried out, and after annealing and heat preservation in a nitrogen atmosphere, the defect-regulated barium titanate composite material is obtained.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of barium titanate preparation, and particularly relates to a preparation method of a defect-regulated barium titanate composite material. BACKGROUND

[0002] Barium titanate, as a core raw material of titanate series electronic ceramics, plays a crucial role in the field of electronic ceramics. Its outstanding dielectric properties, including high dielectric constant and low dielectric loss, as well as excellent ferroelectric, piezoelectric, voltage resistance and insulation characteristics, enable barium titanate to excel in the manufacture of ceramic sensitive elements. Barium titanate is crucial in the field of electronic ceramics due to its excellent dielectric and ferroelectric properties. In particular, in the fields of PTC thermistors, multilayer ceramic capacitors (MLCCs), grain boundary layer capacitors, thermoelectric elements, piezoelectric ceramics, sonar, sensors, electro-optic display panels, polymer-based composites, and coatings, barium titanate plays an indispensable role. Traditional solid-phase method involves high-temperature calcination of a mixture of barium carbonate and titanium dioxide. The particle size of the powder after reaction is usually in the micron level, and the particles are prone to agglomeration, making subsequent processing difficult.

[0003] Barium titanate (BaTiO3) is an important electronic material, and its crystal structure is crucial for understanding its properties and applications. Changes in the crystal structure of BaTiO3 directly affect its electrical properties. By controlling the particle size, BaTiO3 with specific properties can be prepared. Changes in the crystal structure of barium titanate directly affect its electrical properties. Therefore, through in-depth study of its crystal structure, its unique physical and chemical properties can be better understood, providing strong support for its application in the field of electronic components. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of a defect-regulated barium titanate composite material, which has the effect of convenient opening and closing.

[0005] The above technical purpose of the present application is achieved by the following technical scheme: a preparation method of a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0006] S1: a proper amount of barium carbonate, titanium dioxide, nickel oxide, and dopant mixed powder is added to a ball mill tank, zirconium oxide grinding balls are added, ethanol is used as a ball milling solvent, and ball milling is performed for 20-25 h. Then, the wet material is dried at 80℃ for 12 h, then sieved, and the uniformly mixed powder is calcined in a muffle furnace at 800-1000℃ for 2-3 h; obtaining initial barium titanate composite particles;

[0007] S2: the initial barium titanate composite particles obtained in step S1 are dispersed in an aqueous solution of a growth inhibitor, heated in a water bath at 150-200℃ for 4 h with stirring, then washed, dried, and ground to obtain modified barium titanate composite powder;

[0008] S3: the barium titanate composite powder obtained in step S2 is mixed with a binder polyvinyl butyral to press into a green body, cold isostatic pressing is performed, then the sintering temperature is raised to 1300-1400 DEG C, the sintering time is 4-5h, the annealing temperature under nitrogen atmosphere is 1250-1270 DEG C, and the holding time is 20-30min; a defect-regulated barium titanate composite material is obtained.

[0009] By adopting the technical scheme, the barium titanate composite ceramic medium is prepared by special chemical material construction and optimization of a sintering process, and the barium titanate composite ceramic medium has good dielectric and energy storage temperature stability and high energy storage efficiency by introducing the dopant.

[0010] Meanwhile, the valence state of the nickel element is studied by X-ray photoelectron spectroscopy, and it is found that the nickel exists in two valence states, Ni 2+ is easily oxidized to Ni 3+ , 2+ and Ni 3+ coexist, which will inevitably form oxygen vacancies to balance the charge, which may help to increase the grain size.

[0011] The further setting of the application is that the dopant is Bi (Zr 0.25 Sn 0.5 )O3.

[0012] The further setting of the application is that the dopant is prepared by the following method: (1) bismuth trioxide, zirconium dioxide and tin dioxide are fully mixed in a mass ratio of 1:0.5:1, and ball milling is performed in an ethanol medium for 15-18h; (2) the slurry is dried after sieving, then the raw material powder is chemically reacted and CO2 is removed by sintering at 900-1000 DEG C for 3h, and secondary ball milling is performed for 12h after sintering to obtain the Bi (Zr 0.25 Sn 0.5 )O3 dopant.

[0013] By adopting the technical scheme, the dopant disturbs the coupling of the polarized substances to form a polar nanoregion, induces the material to have a relaxation behavior, significantly improves the microstructure stability and reduces the polarization loss in the alternating electric field, and improves the energy storage efficiency, which shows that Bi 3+ , Zr 4+and Sn 4+ The random occupation of A / B sites leads to the increase of ion disorder degree in the ceramic, and causes the relaxation behavior of short-range polarization mismatch, and after the introduction of the dopant, the barium titanate ceramic shows good relaxation behavior, which is helpful for fast response under the applied electric field, reduces the polarization loss and improves the energy storage efficiency, and can be converted into long-range ferroelectric ordered structure at high electric field, and almost restores the original state after removing the electric field, which is beneficial to realize high polarization intensity and low residual polarization intensity, improve the energy storage density and energy storage efficiency, and meanwhile, the increase of ion disorder degree caused by the doping destroys the long-range dipole interaction, which is crucial for improving the energy storage density and energy storage efficiency, and the oxygen vacancy defect in the barium titanate ceramic is a key factor limiting the further improvement of the breakdown strength.

[0014] The growth inhibitor includes one of sodium stearate, barium acetylacetone and glucose.

[0015] By adopting the technical scheme,.

[0016] The further setting of the application is that the specific preparation method of the step S2 is that: a proper amount of water, initial barium titanate composite particles and growth inhibitor are stirred and mixed for 30-50 min, and then reacted in a hydrothermal reaction kettle at 180-200 DEG C for 5-6 h, and after washing, drying and grinding, the modified barium titanate composite powder is obtained.

[0017] The further setting of the application is that the volume mass concentration of the water, initial barium titanate composite particles and growth inhibitor is 15-20 mL: 1 g: 0.01 g.

[0018] The further setting of the application is that the amount-of-substance ratio of the mixed powder of barium carbonate, titanium oxide and dopant in the step S1 is 1: 1-1.1: 0.9-1.

[0019] By adopting the technical scheme, the carbon-coated barium titanate material is prepared by the method of hydrothermal coating. The carbon coating layer plays a role of growth inhibitor on the one hand, and limits the growth of particles at high temperature on the other hand. The carbon coating layer can be effectively removed during high-temperature calcination. Since the powder dispersibility and uniformity are improved under the action of the growth inhibitor, the dense barium titanate composite powder is prepared at a lower temperature, the agglomeration coefficient is reduced, and the dielectric constant is also improved.

[0020] The further setting of the application is that the amount-of-substance ratio of the mixed powder of barium carbonate, titanium oxide and dopant in the step S1 is 1: 1-1.1: 0.9-1.

[0021] The application has the beneficial effects that:

[0022] 1、The present application is prepared by special chemical material construction and optimization of sintering process and the like way to prepare a kind of environmental protection type barium titanate ceramic medium, by introducing dopant makes it have good dielectric and energy storage temperature stability and higher energy storage efficiency, at the same time, the modified barium titanate in the application is annealed in nitrogen, has local 90 degree domain structure and wedge-shaped domain structure, nitrogen annealing is conducive to the " soft " performance. Not only makes the sample " soft " performance after nitrogen annealing has been restored, also has the characteristics of " hard ", so as to realize the excellent comprehensive piezoelectric performance, at the same time, it has good resonance or anti-resonance characteristics, and has enough phase inversion.

[0023] 2、Dopant forms polar nanoregion by disturbing the coupling of polarized substances, induces the relaxation behavior of the material, significantly improves the microstructure stability and reduces the polarization loss in alternating electric field, improves the energy storage efficiency, shows Bi 3+ , Zr 4+ And Sn 4 + The random occupation of A / B site leads to the increase of ion disorder degree in the ceramic, causing the relaxation behavior of short-range polarization mismatch, after introducing the dopant, the barium titanate ceramic shows good relaxation behavior, which is helpful to the rapid response under the applied electric field, reduces the polarization loss and improves the energy storage efficiency, which can be converted into long-range ferroelectric ordered structure at high electric field, and almost restores the original state after removing the electric field, which is beneficial to realize high polarization intensity and low residual polarization intensity, improve the energy storage density and energy storage efficiency, at the same time, the increase of ion disorder degree caused by doping destroys the interaction of long-range dipole, which is crucial to improve the energy storage density and energy storage efficiency, and the oxygen vacancy defect in barium titanate ceramic is the key factor to limit the further improvement of breakdown strength.

[0024] 3、The present application prepares carbon-coated barium titanate material by hydrothermal coating method. The carbon coating layer plays the role of growth inhibitor on the one hand, limits the growth of particles at high temperature, and on the other hand can play the role of isolation between particles, avoiding the fusion growth of barium titanate particles at high temperature, at the same time, the carbon coating layer can be effectively removed during high temperature calcination. Because the powder dispersibility and uniformity are improved under the action of growth inhibitor, so the dense barium titanate composite powder is prepared at lower temperature, the agglomeration coefficient decreases, and the dielectric constant also increases. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0026] Example 1

[0027] A preparation method of a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0028] S1: mixing powders of barium carbonate, titanium dioxide, nickel oxide, Bi(Zr 0.25 Sn 0.5 )O3 in a molar ratio of 1:1-1.1:0.3-0.6:0.9-1 into a ball mill jar, adding zirconium oxide grinding balls, using ethanol as a ball milling solvent, ball milling for 20-25 h, then drying the wet material at 80°C for 12 h, then sieving, and then calcining the uniformly mixed powders in a muffle furnace at 800-1000°C for 2-3 h; obtaining initial barium titanate composite particles;

[0029] S2: stirring and mixing appropriate amounts of water, the initial barium titanate composite particles and sodium stearate for 30-50 min, then reacting in a hydrothermal reaction kettle at 180-200°C for 5-6 h, and then obtaining modified barium titanate composite powder after washing, drying and grinding; the volume mass concentration of water, the initial barium titanate composite particles and sodium stearate is 15-20 mL:1 g:0.01 g.

[0030] S3: mixing the barium titanate composite powder obtained in step S2 with a binder polyvinyl butyral to press into a green body, performing cold isostatic pressing, then increasing the sintering temperature to 1350°C, sintering for 4-5 h, annealing at 1250-1270°C in a nitrogen atmosphere, and holding for 20-30 min; obtaining a defect-regulated barium titanate composite material.

[0031] Example 2

[0032] A preparation method of a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0033] S1: mixing powders of barium carbonate, titanium dioxide, nickel oxide, Bi(Zr 0.25 Sn 0.5 )O3 in a molar ratio of 1:1-1.1:0.3-0.6:0.9-1 into a ball mill jar, adding zirconium oxide grinding balls, using ethanol as a ball milling solvent, ball milling for 20-25 h, then drying the wet material at 80°C for 12 h, then sieving, and then calcining the uniformly mixed powders in a muffle furnace at 800-1000°C for 2-3 h; obtaining initial barium titanate composite particles;

[0034] S2: Stir and mix appropriate amount of water, initial barium titanate composite particles and barium acetylacetonate for 30-50 min, then react in a hydrothermal reactor at 180-200℃ for 5-6 h, and then obtain modified barium titanate composite powder after washing, drying and grinding; the volume-mass concentration of water, initial barium titanate composite particles and barium acetylacetonate is 15-20 mL: 1 g: 0.01 g.

[0035] S3: Mix the barium titanate composite powder obtained in step S2 with the binder polyvinyl butyral to press into a green body, perform cold isostatic pressing, then the sintering temperature is raised to 1350℃, the sintering time is 4-5 h, the annealing temperature in a nitrogen atmosphere is 1250-1270℃, and the holding time is 20-30 min; obtain a defect-regulated barium titanate composite material.

[0036] Example 3

[0037] A method for preparing a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0038] S1: Mix barium carbonate, titanium dioxide, nickel oxide and Bi(Zr 0.25 Sn 0.5 )O3 in a molar ratio of 1:1-1.1:0.3-0.6:0.9-1 into a ball mill jar, add zirconium oxide grinding balls, and ethanol as a ball milling solvent, and ball mill for 20-25 h, then dry the wet material at 80℃ for 12 h, then sieve, and then calcine the uniformly mixed powder in a muffle furnace at 800-1000℃ for 2-3 h; obtain initial barium titanate composite particles;

[0039] S2: Stir and mix appropriate amount of water, initial barium titanate composite particles and barium acetylacetonate for 30-50 min, then react in a hydrothermal reactor at 180-200℃ for 5-6 h, and then obtain modified barium titanate composite powder after washing, drying and grinding; the volume-mass concentration of water, initial barium titanate composite particles and barium acetylacetonate is 15-20 mL: 1 g: 0.01 g.

[0040] S3: Mix the barium titanate composite powder obtained in step S2 with the binder polyvinyl butyral to press into a green body, perform cold isostatic pressing, then the sintering temperature is raised to 1350℃, the sintering time is 4-5 h, the annealing temperature in a nitrogen atmosphere is 1250-1270℃, and the holding time is 20-30 min; obtain a defect-regulated barium titanate composite material.

[0041] Example 4

[0042] A method for preparing a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0043] S1: a mixture of barium carbonate and titanium dioxide powders in a molar ratio of 1:1-1.1 is added to a ball mill tank, zirconium oxide grinding balls are added, ethanol is used as a ball milling solvent, and ball milling is performed for 20-25 h, then the wet material is dried at 80°C for 12 h, then sieving is performed, and then the uniformly mixed powder is calcined in a muffle furnace at 800-1000°C for 2-3 h; initial barium titanate composite particles are obtained;

[0044] S2: an appropriate amount of water, the initial barium titanate composite particles, and glucose are stirred and mixed for 30-50 min, then a hydrothermal reaction kettle at 180-200°C is used for reaction for 5-6 h, and then modified barium titanate composite powder is obtained after washing, drying, and grinding; the volume-mass concentration of water, the initial barium titanate composite particles, and glucose is 15-20 mL:1 g:0.01 g.

[0045] S3: the barium titanate composite powder obtained in step S2 is mixed with a binder polyvinyl butyral to press into a green body, cold isostatic pressing is performed, then the sintering temperature is raised to 1350°C, the sintering time is 4-5 h, the annealing temperature under a nitrogen atmosphere is 1250-1270°C, and the holding time is 20-30 min; a defect-regulated barium titanate composite material is obtained.

[0046] Example 5

[0047] A preparation method of a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0048] S1: a mixture of barium carbonate, titanium dioxide, and nickel oxide powders in a molar ratio of 1:1-1.1:0.3-0.6 is added to a ball mill tank, zirconium oxide grinding balls are added, ethanol is used as a ball milling solvent, and ball milling is performed for 20-25 h, then the wet material is dried at 80°C for 12 h, then sieving is performed, and then the uniformly mixed powder is calcined in a muffle furnace at 800-1000°C for 2-3 h; initial barium titanate composite particles are obtained;

[0049] S2: an appropriate amount of water, the initial barium titanate composite particles, and glucose are stirred and mixed for 30-50 min, then a hydrothermal reaction kettle at 180-200°C is used for reaction for 5-6 h, and then modified barium titanate composite powder is obtained after washing, drying, and grinding; the volume-mass concentration of water, the initial barium titanate composite particles, and glucose is 15-20 mL:1 g:0.01 g.

[0050] S3: the barium titanate composite powder obtained in step S2 is mixed with a binder polyvinyl butyral to press into a green body, cold isostatic pressing is performed, then the sintering temperature is raised to 1350°C, the sintering time is 4-5 h, the annealing temperature under a nitrogen atmosphere is 1250-1270°C, and the holding time is 20-30 min; a defect-regulated barium titanate composite material is obtained.

[0051] Example 6

[0052] A preparation method of a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0053] S1: mixed powders of barium carbonate, titanium dioxide, Bi(Zr 0.25 Sn 0.5 )O3 in a molar ratio of 1:1-1.1:0.9-1 are added into a ball mill tank, zirconium oxide grinding balls are added, ethanol is used as a ball milling solvent, and ball milling is performed for 20-25 h, then the wet material is dried at 80°C for 12 h, then sieving is performed, and then the uniformly mixed powders are calcined in a muffle furnace at 800-1000°C for 2-3 h; initial barium titanate composite particles are obtained;

[0054] S2: an appropriate amount of water, the initial barium titanate composite particles and glucose are stirred and mixed for 30-50 min, then a hydrothermal reaction kettle at 180-200°C is used for reaction for 5-6 h, and after washing, drying and grinding, modified barium titanate composite powders are obtained; the volume mass concentration of water, the initial barium titanate composite particles and glucose is 15-20 mL:1 g:0.01 g.

[0055] S3: the barium titanate composite powders obtained in step S2 are mixed with a binder polyvinyl butyral to press into green bodies, cold isostatic pressing is performed, then the sintering temperature is increased to 1350°C, the sintering time is 4-5 h, the annealing temperature in a nitrogen atmosphere is 1250-1270°C, and the holding time is 20-30 min; a defect-regulated barium titanate composite material is obtained.

[0056] Example 7

[0057] A preparation method of a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0058] S1: mixed powders of barium carbonate, titanium dioxide, Bi(Zr 0.25 Sn 0.5 )O3 in a molar ratio of 1:1-1.1:0.3-0.6:0.9-1 are added into a ball mill tank, zirconium oxide grinding balls are added, ethanol is used as a ball milling solvent, and ball milling is performed for 20-25 h, then the wet material is dried at 80°C for 12 h, then sieving is performed, and then the uniformly mixed powders are calcined in a muffle furnace at 800-1000°C for 2-3 h; initial barium titanate composite particles are obtained;

[0059] S2: Stir and mix appropriate amount of water, initial barium titanate composite particles and glucose for 30-50 min, then react in a hydrothermal reactor at 180-200 ℃ for 5-6 h, and then obtain modified barium titanate composite powder after washing, drying and grinding; the volume mass concentration of water, initial barium titanate composite particles and glucose is 15-20 mL: 1 g: 0.01 g.

[0060] S3: Mix the barium titanate composite powder obtained in step S2 with the binder polyvinyl butyral, press into a green body, perform cold isostatic pressing, then the sintering temperature is raised to 1350 ℃, the sintering time is 4-5 h, and after cooling, a defect-regulated barium titanate composite material is obtained.

[0061] Example 8

[0062] A preparation method of a defect-regulated barium titanate composite material, comprising the following preparation steps:

[0063] S1: Mix barium carbonate, titanium dioxide, nickel oxide and Bi(Zr 0.25 Sn 0.5 )O3 mixed powder in a molar ratio of 1:1-1.1:0.3-0.6:0.9-1 into a ball mill jar, add zirconium oxide grinding balls, and ethanol as a ball milling solvent, ball mill for 20-25 h, then dry the wet material at 80 ℃ for 12 h, then sieve, and then calcine the uniformly mixed powder in a muffle furnace at 800-1000 ℃ for 2-3 h; obtain initial barium titanate composite particles;

[0064] S2: Mix the initial barium titanate composite particles obtained in step S1 with the binder polyvinyl butyral, press into a green body, perform cold isostatic pressing, then the sintering temperature is raised to 1350 ℃, the sintering time is 4-5 h, the annealing temperature is 1250-1270 ℃ under a nitrogen atmosphere, and the holding time is 20-30 min; obtain a defect-regulated barium titanate composite material.

[0065] Comparative Example 1

[0066] A preparation method of barium titanate, comprising the following preparation steps:

[0067] S1: Mix barium carbonate and titanium dioxide mixed powder in a molar ratio of 1:1-1.1 into a ball mill jar, add zirconium oxide grinding balls, and ethanol as a ball milling solvent, ball mill for 20-25 h, then dry the wet material at 80 ℃ for 12 h, then sieve, and then calcine the uniformly mixed powder in a muffle furnace at 800-1000 ℃ for 2-3 h; obtain initial barium titanate composite particles;

[0068] S2: The initial barium titanate composite particles obtained in step S1 are mixed with a binder polyvinyl butyral and pressed into a green body, cold isostatic pressing is performed, and then the sintering temperature is raised to 1350°C, the sintering time is 4-5h, and after cooling, a defect-regulated barium titanate composite material is obtained.

[0069] The performance of each defect-regulated barium titanate composite material obtained in Comparative Example 1 and Examples 1-8 is detected, and Table 1 is obtained

[0070] Ceramic density / g / cm 3 ]]> dielectric constant grain size / μm aggregation coefficient example 1 6.02 3036 1.44 1.105 example 2 6.08 3041 1.46 1.092 example 3 6.12 3058 1.51 1.046 example 4 5.71 2848 1.28 1.134 example 5 5.78 2854 1.35 1.126 example 6 5.87 2861 1.27 1.112 example 7 5.94 2942 1.55 1.092 example 8 5.63 2743 1.76 1.38 comparative example 1 5.17 2651 5.8 1.64

[0071] As can be seen from the above table, Examples 1-3 all exhibit high ceramic density and dielectric constant, and the agglomeration coefficient is low. This is because a barium titanate composite ceramic medium is prepared by special chemical material construction and optimization of the sintering process, etc. By introducing a dopant, it has good dielectric and energy storage temperature stability and high energy storage efficiency. By the method of hydrothermal coating, a carbon-coated barium titanate material is prepared. The carbon coating layer plays a role of growth inhibitor on the one hand, limiting the growth of particles at high temperature, and on the other hand, it can play an isolation role between particles, avoiding the fusion and growth of barium titanate particles at high temperature, so that the grain uniformity increases.

Claims

1. A method for preparing a defect-engineered barium titanate composite material, characterized by: The preparation steps include: S1: a proper amount of barium carbonate, titanium dioxide, nickel oxide, and dopant mixed powder is added into a ball mill tank, zirconium oxide grinding balls are added, ethanol is used as a ball milling solvent, and ball milling is performed for 20-25 h, then the wet material is dried at 80℃ for 12 h, then sieving is performed, and then the uniformly mixed powder is calcined in a muffle furnace at 800-1000℃ for 2-3 h; an initial barium titanate composite particle is obtained; S2: the initial barium titanate composite particle obtained in step S1 is dispersed in an aqueous solution of a growth inhibitor, water bath heating and stirring are performed at 150-200℃ for 4 h, then washing, drying, and grinding are performed to obtain a modified barium titanate composite powder; S3: the barium titanate composite powder obtained in step S2 is mixed with a binder polyvinyl butyral to press into a green body, cold isostatic pressing is performed, then the sintering temperature is increased to 1300-1400℃, the sintering time is 4-5 h, the annealing temperature is 1250-1270℃ under a nitrogen atmosphere, and the holding time is 20-30 min; a defect-regulated barium titanate composite material is obtained; The dopant is Bi(Zr 0.25 Sn 0.5 )O3; The dopant is prepared by the following method: (1) mixing bismuth trioxide, zirconium dioxide and tin dioxide in a mass ratio of 1:0.5:1, and ball milling in an ethanol medium for 15-18 h; (2) sieving the slurry, drying, and then sintering the raw material powder at 900-1000 DEG C for 3 h to cause a chemical reaction and remove CO2, and then secondarily ball milling for 12 h to obtain a Bi(Zr 0.25 Sn 0.5 )O3 dopant; the growth inhibitor comprises one of sodium stearate, barium acetylacetone and glucose. in step S1, the amount-of-substance ratio of the barium carbonate, titanium dioxide, and dopant mixed powder is 1:1-1.1:0.9-1; the amount-of-substance ratio of the titanium dioxide and nickel oxide is 1:0.3-0.

6.

2. The method of claim 1, wherein the method comprises: the volume mass concentration of the water, initial barium titanate composite particle, and growth inhibitor is 15-20 mL:1 g:0.01 g.