Method for producing doped barium / lithium nanotitanium powder material, and use thereof

Abstract

This invention relates to a method for producing doped barium / lithium nanotitanate powder material and its use. An intermetallic compound in which the doped element is solid-solved is used as a precursor and reacted with a base solution to obtain a non-spherical nanotitanate intermediate product, and then this intermediate powder product is Ba 2+ / Li + By reacting a barium / lithium source material containing the specified substance with a medium atmosphere at a predetermined temperature, pressure, and for a set period of time, the non-spherical nanotitanate intermediate product undergoes a cation substitution reaction and a "spheroidization" morphological change, yielding spherical or nearly spherical in-situ intrinsically doped barium / lithium nanotitanate particle powder product. This manufacturing method is characterized by its simple process, ease of operation, and low cost. The manufactured in-situ intrinsically doped barium / lithium titanate nanoparticle powder material is expected to have good applications in fields such as electronic ceramics, composite materials, paints, powder metallurgy, multilayer ceramic capacitors, thermistors, piezoelectric ceramics, and battery materials.

Description

[Technical Field]

[0001] This invention relates to the technology of nanomaterials, and more particularly to a method for producing doped barium / lithium nanotitanium powder material and its use. [Background technology]

[0002] Barium titanate (BaTiO3) is a very typical perovskite crystal structure with characteristics such as high dielectric constant, low dielectric loss, high resistance, high compressive strength, and excellent insulation properties, making it an important basic raw material for multilayer ceramic capacitors (MLCCs). By doping barium titanate with various elements such as rare earth elements, the performance of MLCCs can be further improved. Lithium titanate (Li4Ti5O3) 12 Barium titanate / lithium titanate is a type of lithium titanium composite oxide with a spinel structure. In the field of battery materials, it offers advantages such as good cycle performance, high chemical stability, low hygroscopicity in a fully charged state, and thermal stability. It can be used in the stable voltage range of most liquid electrolytes and is widely used in lithium-ion batteries and asymmetric supercapacitors. Currently, the main methods for producing barium titanate / lithium titanate are solid-phase synthesis, chemical precipitation, hydrothermal, sol-gel, and alcohol salt hydrolysis. These methods are unsuitable for large-scale and low-cost production of barium titanate / lithium titanate because they result in non-uniform sintered particle sizes and require complex equipment conditions.

[0003] Currently, the most effective methods for producing doped barium titanate particles are the hydrothermal method and the sol-gel method. In both methods, a gel or suspension containing a barium titanate precursor is first prepared, the substance to be doped is added, and then doped barium titanate powder is obtained by hydrothermal treatment or sintering. However, this doping method can only provide a uniform doping effect to a portion of the doped material. Therefore, developing new doping routes and methods to significantly and cost-effectively increase the types of elements that can be doped and the doping content is of great significance for the application of doped barium titanate. [Overview of the project] [Problems that the invention aims to solve]

[0004] Based on this, there is a need to provide a method for mass-producing doped barium / lithium nanotitanium at low cost to address the technical challenges mentioned above. [Means for solving the problem]

[0005] The method for producing doped barium / lithium nanotitanium powder is characterized by comprising the following manufacturing steps.

[0006] Step 1: A starting alloy is manufactured, the starting alloy containing T, Ti, and E elements, the phase composition of the starting alloy containing a T-Ti(E) intermetallic compound in which E is in solid solution, or a T-Ti-E intermetallic compound containing E, where the molar ratio of E to Ti in the T-Ti(E) intermetallic compound or T-Ti-E intermetallic compound is 0 ≤ C E / C Ti The ratio is ≤0.30, element T includes at least one of Al and Zn, and element E includes at least one of Zr, Hf, Cr, V, Nb, Ta, W, Mo, Mn, Fe, Ni, Co, Sn, Pb, Bi, B, Be, Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, and RE, where RE includes at least one rare earth element.

[0007] In step 2, the initial alloy is subjected to a hydrogen deposition and de-T reaction with a base solution mainly consisting of NaOH / KOH to obtain an intermediate powder product whose composition mainly includes at least one of the following: a nanosodium / potassium titanate thin film powder in which element E is intrinsically doped in situ; a nanoporous sodium / potassium titanate disordered powder in which element E is intrinsically doped in situ; and a nanosodium / potassium titanate tube (rod) in which element E is intrinsically doped in situ.

[0008] Alternatively, an intermediate powder product consisting of sodium / potassium nanotitanate intrinsically doped with element E in situ is reacted with a dilute acid to obtain an intermediate powder product of nanotitanate intrinsically doped with element E substituted with hydrogen ions, the composition of which mainly comprises at least one of a nanotitanate thin film powder intrinsically doped with element E in situ, a nanoporous titanate disordered powder intrinsically doped with element E in situ, and a nanotitanate tube (rod) intrinsically doped with element E in situ.

[0009] In step 3, the above intermediate powder product is subjected to a predetermined temperature, pressure, and medium atmosphere, Ba 2+ / Li + By reacting the contained barium / lithium source material with the non-spherical intermediate powder product for a certain period of time, the non-spherical intermediate powder product undergoes a cation substitution reaction and a "spheroidization" morphological change, yielding a barium / lithium nanotitanate particle powder product in which spherical or nearly spherical E elements are intrinsically doped in situ.

[0010] In step 1 above,

[0011] Furthermore, the above element T contains Al, and furthermore, element T is Al.

[0012] Furthermore, the above element T contains Zn, and furthermore, element T is Zn.

[0013] Furthermore, the above-mentioned element T includes Al and Zn.

[0014] Furthermore, the above RE contains at least one of rare earth elements Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.

[0015] Furthermore, the above E element contains at least one of Zr, Hf, Cr, V, Nb, Ta, W, Mo, Mn, Sn, Pb, Bi, B, Be, RE.

[0016] Furthermore, the above E element contains at least one of Zr, Hf, Cr, V, Nb, Ta, W, Mo.

[0017] Furthermore, the above E element contains at least one of Mn, Sn, Pb, Bi, B, Be.

[0018] Furthermore, the above E component element mainly contains Ag, and the atomic percentage content of Ag in the E element exceeds 50%.

[0019] Furthermore, the above E component element mainly contains RE.

[0020] Furthermore, when CE / CTi = 0, that is, when the initial alloy does not contain mold elements, the subsequent product does not contain doped E elements.

[0021] Furthermore, 0 ≦ C E / C Ti ≦ 0.25, and furthermore, 0 ≦ CE / CTi ≦ 0.20, and furthermore, 0 ≦ C E / C Ti ≦ 0.10.

[0022] Furthermore, 0 < CE / CTi ≦ 0.30, and furthermore, 0 < CE / CTi ≦ 0.25, and furthermore, 0 < CE / CTi ≦ 0.20, and furthermore, 0 < CE / CTi ≦ 0.10.

[0023] Furthermore, the phase composition of the above initial alloy is mainly composed of a T-Ti(E) intermetallic compound in which the E element is dissolved, or a T-Ti-E intermetallic compound containing the E element.

[0024] Furthermore, a T-Ti(E) intermetallic compound in which the above-mentioned E component element is in solid solution means that the E component element exists in the interstitial gaps of the T-Ti(E) intermetallic compound in the form of interstitial atoms, or that the E component element substitutes for T or Ti atomic positions in the lattice of the T-Ti(E) intermetallic compound in the form of substitution atoms.

[0025] Furthermore, the above-mentioned solid solution includes interstitial solid solution and substitutional solid solution.

[0026] Furthermore, the T-Ti-E intermetallic compound containing the above-mentioned element E refers to an intermetallic compound composed of elements T, Ti, and E, and is different from the T-Ti(E) intermetallic compound. In the T-Ti(E) intermetallic compound, element E is dissolved in the T-Ti intermetallic compound, but in the T-Ti-E intermetallic compound, element E is the main component of the T-Ti-E intermetallic compound phase.

[0027] Furthermore, when CE / CTi = 0, the T-Ti(E) intermetallic compound does not contain element E and is therefore a T-Ti intermetallic compound.

[0028] Furthermore, the initial alloy described above is produced by solidifying a molten material containing elements T, Ti, and E. During the solidification process of the alloy, a solidification structure containing T-Ti(E) intermetallic compounds or T-Ti-E intermetallic compounds is formed. Here, element E is mainly dissolved in the T-Ti(E) intermetallic compounds.

[0029] Furthermore, the solidification rate of the initial alloy molten material is 0.01 K / s ~ 10 8 It is K / s.

[0030] Furthermore, generally speaking, the higher the cooling rate, the higher the solid solubility of element E in T-Ti(E) intermetallic compounds. This solid solubility is the solid solubility for non-equilibrium solidification and can be much higher than the solid solubility corresponding to equilibrium solidification.

[0031] Furthermore, the above-mentioned T-Ti(E) intermetallic compound includes at least one of the T3Ti(E), T2Ti(E), and TTi(E) intermetallic compounds.

[0032] Furthermore, the above T-Ti intermetallic compound includes at least one of Al3Ti, Al2Ti, and AlTi intermetallic compounds.

[0033] Furthermore, in the initial alloy, the T-Ti(E) intermetallic compound is composed of one or more sub-T-Ti(E) intermetallic compounds.

[0034] Furthermore, the shape of the initial alloy described above has an average size greater than 2 μm in any of the three dimensions.

[0035] Furthermore, the shape of the initial alloy described above has an average size greater than 5 μm in any of the three dimensions.

[0036] Furthermore, the shape of the initial alloy described above has an average size greater than 10 μm in any of the three dimensions.

[0037] Furthermore, the shape of the initial alloy described above includes at least one of the following: lump-like, granular, filamentous, strip-like, ribbon-like, and flake-like.

[0038] Furthermore, the initial alloy described above is in the form of a powder or ribbon, and the powder particles or ribbons have at least one dimension in the three-dimensional direction that is less than 500 μm.

[0039] Preferably, the initial alloy is in the form of a powder or ribbon, and the powder particles or ribbons have at least one dimension in the three-dimensional direction of less than 200 μm.

[0040] Preferably, the initial alloy is in the form of a powder or ribbon, and the powder particles or ribbons have at least one dimension in the three-dimensional direction of less than 50 μm.

[0041] Furthermore, if the initial alloy is in the form of a ribbon, it can be manufactured by a method including molten strip casting.

[0042] Furthermore, if the initial alloy is in powder form, a larger initial alloy ingot can be produced by casting, and then crushed to obtain the initial alloy powder.

[0043] In step 2 described above,

[0044] Furthermore, the above base solution includes at least one of NaOH and KOH solutions.

[0045] Preferably, the solvent of the above base solution is mainly water.

[0046] Furthermore, the concentration of the base in the above base solution is 2.1 to 30 mol / L, preferably 2.1 to 15 mol / L.

[0047] Furthermore, the concentration of the above base solution refers to the effective concentration of NaOH / KOH in the base, and in this invention, we have found that only the effective concentration of NaOH / KOH is meaningful. Specifically, in the alkaline solution, OH derived from relatively weak bases such as LiOH, RbOH, Ba(OH)2, Ca(OH)2, and Sr(OH)2 is used. - If they also exist, - The total content is due to the contribution of OH from NaOH and KOH. - Although higher than the content, this relatively weak base contribution of OH - The content does not play a significant role when the initial alloy forms the predetermined intermediate powder product described in step 2 by hydrogen deposition and de-T reaction.

[0048] Furthermore, since the NaOH / KOH in the base solution reacting with the initial alloy is in excess, the reaction can proceed at a higher base concentration.

[0049] Furthermore, the NaOH / KOH content in the base solution reacting with the initial alloy is more than five times the required reaction dose.

[0050] Furthermore, the NaOH / KOH content in the base solution reacting with the initial alloy is more than 10 times the required reaction dose.

[0051] The higher the concentration of NaOH / KOH and the higher the temperature, the more vigorous the reaction with the initial alloy becomes.

[0052] The hydrogen deposition and T removal reaction described above refers to the reaction in which, when an initial alloy is reacted with a base solution and an NaOH / KOH solution, T dissolves in the salt due to the base and is mixed into the solution, while hydrogen gas is simultaneously released.

[0053] Furthermore, the initial alloy is reacted with a base solution having NaOH / KOH as its main composition to obtain different intermediate powder products under different reaction conditions.

[0054] 1) Under normal pressure, when the NaOH / KOH concentration is high and the temperature of the base solution is high, the intermediate powder product mainly consists of sodium / potassium nanotitanate thin film powder in which element E is endogenously doped in situ.

[0055] Preferably, by controlling the NaOH / KOH concentration and temperature, if the reaction interface advances inward from the surface of the initial alloy at an average rate of 10 μm / min or more during the reaction between the initial alloy and the base solution mainly composed of NaOH / KOH, the intermediate powder product mainly consists of a sodium / potassium nanotitanate thin film powder in which element E is intrinsically doped in-situ.

[0056] Preferably, the NaOH / KOH concentration range is 5.1 to 30 mol / L, the temperature of the base solution is above 100°C, and the boiling point T of the base solution at this concentration is... f溶液 In the following cases, the intermediate powder product mainly consists of a sodium / potassium nanotitanate thin film powder in which element E is intrinsically doped in situ.

[0057] Preferably, the concentration range of NaOH / KOH is 7.5 to 30 mol / L, and the temperature is the boiling point T of the base solution of this concentration. f溶液In this case, the intermediate powder product mainly consists of a sodium / potassium nanotitanate thin film powder in which element E is intrinsically doped in situ.

[0058] At normal pressure, the boiling point of water is 100°C. When a base is dissolved in water, the boiling point of the base solution at 1 standard atmospheric pressure is higher than 100°C, and the boiling point increases with increasing base concentration. For example, the boiling point of a 5.1 mol / L sodium hydroxide solution... Tf溶液 It is approximately 108°C, and the boiling point of a 7 mol / L sodium hydroxide aqueous solution. Tf溶液 It is approximately 112°C, and is the boiling point of a 10 mol / L sodium hydroxide aqueous solution. Tf溶液 It is approximately 119°C, and is the boiling point of a 12 mol / L sodium hydroxide aqueous solution. Tf溶液 It is approximately 128°C, and the boiling point of a 15 mol / L sodium hydroxide aqueous solution. Tf溶液 The boiling point is approximately 140°C, and is the boiling point of a 17 mol / L sodium hydroxide aqueous solution. Tf溶液 It is approximately 148°C, and the boiling point of a 20 mol / L sodium hydroxide aqueous solution. Tf溶液 It is approximately 160°C, and is the boiling point of a 25 mol / L sodium hydroxide aqueous solution. Tf溶液 It is approximately 180°C, and is the boiling point of a 10 mol / L potassium hydroxide aqueous solution. Tf溶液 It is approximately 125°C, and the boiling point of a 12 mol / L potassium hydroxide aqueous solution. Tf溶液 It is approximately 136°C, and is the boiling point of a 15 mol / L potassium hydroxide aqueous solution. Tf溶液 The temperature is approximately 150°C.

[0059] During the reaction process, the initial alloy undergoes nanofragmentation through vigorous hydrogen deposition and de-T removal, followed by reconstruction of its shape and composition to produce a sodium / potassium titanate thin film powder intrinsically doped with element E in situ.

[0060] The occurrence of the above nano-fragmentation and reconstruction of shape and composition means that the T-Ti(E) intermetallic compound phase or T-Ti-E intermetallic compound phase in the initial alloy is fragmented by hydrogen deposition and de-T reactions into nano-sodium / potassium titanate thin films with at least one dimension (i.e., thickness) of less than 5 nm in the three-dimensional direction.

[0061] Furthermore, the thickness of the sodium / potassium nanotitanate thin film in which the above-mentioned element E is intrinsically doped in situ is less than 5 nm.

[0062] Furthermore, the thickness range of the sodium / potassium nanotitanate thin film in which the above-mentioned element E is intrinsically doped in situ is 0.25 nm to 4 nm.

[0063] Furthermore, the thickness range of the sodium / potassium nanotitanate thin film in which the above-mentioned element E is intrinsically doped in situ is 0.25 nm to 3 nm.

[0064] Furthermore, the average area of ​​the sodium / potassium nanotitanate thin film in which the above-mentioned element E is intrinsically doped in situ is 500 nm. 2 Larger.

[0065] Furthermore, the average area of ​​the sodium / potassium nanotitanate thin film in which the above element E is intrinsically doped in situ is 1000 nm. 2 Larger.

[0066] Furthermore, the average area of ​​the sodium / potassium nanotitanate thin film in which the above element E is intrinsically doped in situ is 10,000 nm. 2 Larger.

[0067] Furthermore, the sodium / potassium nanotitanate thin film in which the above-mentioned element E is intrinsically doped in situ exhibits low crystallinity.

[0068] Furthermore, the initial alloy is subjected to a hydrogen deposition and de-T reaction with a base solution mainly composed of NaOH / KOH to obtain an intermediate powder product, the composition of which mainly contains a sodium / potassium nanotitanate thin film intrinsically doped with element E in situ.

[0069] The above-mentioned sodium / potassium nanotitanate thin film powder is macroscopically in powder form, but microscopically it is composed of numerous thin films.

[0070] 2) Under normal pressure, with low NaOH / KOH concentrations and low temperatures of the base solution, the intermediate powder product mainly consists of nanoporous sodium / potassium titanate disordered powder in which element E is endogenously doped in situ.

[0071] Preferably, by controlling the NaOH / KOH concentration and temperature, if the reaction interface advances inward from the surface of the initial alloy at an average rate of less than 2 μm / min during the reaction of the initial alloy with a base solution mainly composed of NaOH / KOH, the intermediate powder product mainly consists of nanoporous sodium / potassium titanate disordered powder intrinsically doped with element E in situ.

[0072] Preferably, when the NaOH / KOH concentration range is 2.1 to 15 mol / L and the temperature is less than 60°C, the intermediate powder product mainly consists of a nanoporous sodium / potassium titanate disordered powder in which element E is intrinsically doped in situ.

[0073] The term "irregular powder" refers to the fact that the powder particles undergo a certain degree of initial fragmentation during the reaction process due to the hydrogen generated by the reaction of the initial alloy, and since this fragmentation is random and irregular, the fragmented powder particles have irregular sizes and shapes.

[0074] By making the volume of the irregular powder particles approximately equal to that of the spherical particles, the following results are obtained.

[0075] Furthermore, the D90 particle size of the nanoporous sodium / potassium titanate disordered powder in which the above-mentioned element E is intrinsically doped in situ is greater than 500 nm.

[0076] Furthermore, the D90 particle size of the nanoporous sodium / potassium titanate disordered powder in which the above-mentioned element E is intrinsically doped in situ is greater than 1 μm.

[0077] Furthermore, the D90 particle size of the nanoporous sodium / potassium titanate disordered powder in which the above-mentioned element E is intrinsically doped in situ is greater than 3 μm.

[0078] Furthermore, the average diameter of tethers in the nanoporous sodium titanate / potassium titanate microstructure in the nanoporous sodium titanate / potassium titanate disordered powder in which the above element E is intrinsically doped in situ is less than 10 nm.

[0079] Furthermore, the average diameter of tethers in the nanoporous sodium titanate / potassium titanate microstructure in the nanoporous sodium titanate / potassium titanate disordered powder in which the above element E is intrinsically doped in situ is less than 5 nm.

[0080] Furthermore, the average diameter of tethers in the nanoporous sodium titanate / potassium titanate microstructure in the nanoporous sodium titanate / potassium titanate disordered powder in which the above element E is intrinsically doped in situ is less than 3 nm.

[0081] Furthermore, the nanoporous sodium / potassium titanate disordered powder in which the above element E is intrinsically doped in situ is mainly low in crystalline structure.

[0082] 3) Under normal pressure, with moderate NaOH / KOH concentrations and moderate temperatures of the base solution, the intermediate powder product mainly consists of nanoporous sodium / potassium titanate disordered powder in which element E is endogenously doped in situ, and nanosodium / potassium titanate thin film powder in which element E is endogenously doped in situ.

[0083] Preferably, by controlling the NaOH / KOH concentration and temperature, if the reaction interface advances inward from the surface of the initial alloy at an average rate of 2 μm / min to 10 μm / min during the reaction between the initial alloy and the base solution mainly composed of NaOH / KOH, the intermediate powder product mainly consists of nanoporous sodium / potassium titanate disordered powder in which element E is intrinsically doped in situ and nanoporous sodium / potassium titanate thin film powder intrinsically doped in situ.

[0084] Preferably, when the concentration range of NaOH / KOH is 2.1 to 15 mol / L and the temperature is 60°C to 100°C, the intermediate powder product mainly consists of a nanoporous sodium / potassium titanate disordered powder in which element E is intrinsically doped in situ, and a nanosodium / potassium titanate thin film powder intrinsically doped in situ.

[0085] Furthermore, the nanoporous sodium / potassium titanate disordered powder in which element E is intrinsically doped in situ, and the nanosodium / potassium titanate thin film powder intrinsically doped in situ with element E, are primarily low-crystallinity.

[0086] In the above 1)-3), the reaction time until element T is completely removed from the initial alloy depends on the shape of the initial alloy. The smaller the initial alloy powder particles or the thinner the initial alloy ribbon, the shorter the time required to complete the hydrogen deposition and T removal reaction. Conversely, the time required to complete the hydrogen deposition and T removal reaction is longer. Based on the average rate of reaction at the reaction interface and the size of the initial alloy, the minimum reaction time t required to complete the hydrogen deposition and T removal reaction can be calculated. For example, if the initial alloy is a ribbon of thickness d and the average rate of reaction at the reaction interface is v, then assuming that the reaction proceeds from both the top and bottom of the ribbon, t = 0.5d / v. Similarly, if the initial alloy is a particle of diameter d and the average rate of reaction at the reaction interface is v, then t = 0.5d / v.

[0087] When the concentration of NaOH is 10 mol / L, generally, during the reaction between the initial alloy and the base solution, the hydrogen evolution and de-aluminum reaction interface advances from the surface of the initial alloy towards the inside at the following rate.

[0088] When 60°C ≤ T1 ≤ 80°C, the average advancing rate of the above reaction interface is about 2 μm / min to 7 μm / min.

[0089] When 80°C ≤ T1 ≤ 90°C, the average advancing rate of the above reaction interface is about 7 μm / min to 15 μm / min.

[0090] When 90°C < T1 ≤ 100°C, the average advancing rate of the above reaction interface is about 15 μm / min to 30 μm / min.

[0091] When 100°C < T1 ≤ 110°C, the average advancing rate of the above reaction interface is about 30 μm / min to 50 μm / min.

[0092] When 110°C < T1 < 119°C, the average advancing rate of the above reaction interface is about 50 μm / min to 120 μm / min.

[0093] The average advancing rate of the reaction interface of the initial alloy ribbon is about 120 μm / min (reaction at the boiling point T when the concentration of NaOH is f溶液 10 mol / L). That is, in the case of an initial alloy ribbon with a thickness of 40 μm, the hydrogen evolution and de-aluminum reaction can be completed in 10 seconds; in the case of an initial alloy ribbon with a thickness of 20 μm, the hydrogen evolution and de-aluminum reaction can be completed in 5 seconds; even in the case of an initial alloy sphere with a particle size of 5 mm, the hydrogen evolution and de-aluminum reaction can be completed in 21 minutes.

[0094] Furthermore, the reaction time between the above initial alloy and the base solution is 10 s to 59 min.

[0095] Furthermore, the reaction time between the above initial alloy and the base solution is 10 s to 9.9 min.

[0096] Furthermore, the reaction time between the initial alloy and the base solution is 10 seconds to 2 minutes.

[0097] Furthermore, the reaction time between the initial alloy and the base solution is 10 seconds to 1 minute.

[0098] Furthermore, the reaction time between the initial alloy and the base solution is 10 to 30 seconds.

[0099] Clearly, the higher T1, the thinner the initial alloy, or the smaller the particle size, the shorter the required reaction time. Conversely, the reaction time will be longer.

[0100] Once the hydrogen deposition and de-T reaction is complete, the reaction system reaches equilibrium. At this point, the stability of the product can still be ensured by continuing to extend the time the reaction system is held at the original reaction temperature. Therefore, if the reaction time between the initial alloy and the base solution exceeds the required minimum hydrogen deposition and de-T reaction time t, for example, several hours, the corresponding intermediate product can be obtained.

[0101] 5) The reaction is carried out in a sealed container under pressure higher than atmospheric pressure, with high NaOH / KOH concentrations and a temperature of the boiling point T at 1 atmosphere. f溶液 At temperatures higher than the specified temperature, the intermediate powder product mainly consists of nanotitanium tubes (rods) intrinsically doped with element E in situ.

[0102] Furthermore, the above reaction temperature is T f溶液 It is higher than the temperature and lower than 300°C. Furthermore, the above reaction temperature is T f溶液 It is higher than the temperature and lower than 250°C. Furthermore, the above reaction temperature is T f溶液 It is higher than the temperature but lower than 200°C.

[0103] Furthermore, the above reaction times range from 1 min to 5 hours, and furthermore, from 1 min to 2 hours, and furthermore, from 1 min to 30 minutes.

[0104] Preferably, the NaOH / KOH concentration range is 7.5 to 30 mol / L, and the reaction temperature is T f溶液When the pressure is higher and the atmospheric pressure corresponds to the pressure of a sealed container at the corresponding temperature, the intermediate powder product mainly consists of nanotitanium tubes (rods) intrinsically doped with element E in situ.

[0105] Furthermore, the outer diameter of the nanotitanium tube (rod) in which the above-mentioned element E is intrinsically doped in situ does not exceed 10 nm.

[0106] Furthermore, the outer diameter of the nanotitanium tube (rod) in which the above-mentioned element E is intrinsically doped in situ does not exceed 7.5 nm.

[0107] Furthermore, the nanotitanium tubes (rods) in which the above-mentioned element E is intrinsically doped in situ are mainly crystalline.

[0108] 6) An intermediate powder product consisting of sodium / potassium nanotitanate intrinsically doped in situ with different shapes of element E as described in 1) to 4) above is reacted with a dilute acid to obtain an intermediate powder product of nanotitanate intrinsically doped in situ with element E substituted with hydrogen ions, the composition of which mainly includes at least one of nanotitanate thin film powder intrinsically doped in situ with element E, nanoporous titanate disordered powder intrinsically doped in situ with element E, and nanotitanate tubes (rods) intrinsically doped in situ with element E.

[0109] Furthermore, the hydrogen ion concentration in the above acid solution is 0.001 mol / L to 0.2 mol / L.

[0110] Preferably, the hydrogen ion concentration in the above acid solution is 0.001 mol / L to 0.1 mol / L.

[0111] Preferably, the hydrogen ion concentration in the above acid solution is 0.001 mol / L to 0.05 mol / L.

[0112] Furthermore, except for the change in cations from sodium / potassium ions to hydrogen ions, the various morphological features of nanotitanium thin film powders in which element E is endogenously doped in situ are essentially identical to those of nanosodium / potassium titanate thin film powders in which element E is endogenously doped in situ. The various morphological features of nanoporous titanate disordered powders in which element E is endogenously doped in situ are essentially identical to those of nanoporous sodium / potassium titanate disordered powders in which element E is endogenously doped in situ. The various morphological features of nanotitanium tubes (rods) in which element E is endogenously doped in situ are essentially identical to those of nanosodium / potassium titanate tubes (rods) in which element E is endogenously doped in situ. Each specific feature is as described above.

[0113] In particular, during the reaction of the initial alloy with a base solution mainly composed of NaOH / KOH, or during the reactions 1) to 5) above, the element E is initially dissolved in the T-Ti(E) intermetallic compound in the form of E atoms, or the E atoms are dispersed in the T-Ti-E intermetallic compound. Therefore, the T-Ti(E) intermetallic compound or the T-Ti-E intermetallic compound remains solid before and after the reaction with the NaOH / KOH solution. Consequently, the element E atoms are not easily released during the reaction, and as a result, the intermediate powder product is intrinsically doped with the element E in situ. Depending on the different reaction conditions, a sodium / potassium titanate or titanate intermediate powder product is obtained in which the element E is ultimately intrinsically doped in situ in different forms.

[0114] Furthermore, the basic method of in-situ endogenous doping with element E mainly involves at least one of the following two methods a) and b).

[0115] c) Element E is intrinsically embedded in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles or E oxide nanoparticles. In this case, the E nanoparticles or E oxide nanoparticles are in a different phase from the sodium / potassium titanate or titanate matrix.

[0116] d) Element E is intrinsically embedded in the sodium / potassium titanate or titanate intermediate powder product in the form of E atoms or atomic clusters. In this case, the E atoms or atomic clusters do not form a different phase with respect to the sodium / potassium titanate or titanate matrix, or do not form a distinctly different phase. Here, the size of the E atomic clusters does not exceed 2 nm, and it is difficult to discern the contrast by transmission electron microscopy (TEM) observation. In this case, element E exists in the sodium / potassium titanate or titanate intermediate powder product as a solid solution in the form of E atoms or atomic clusters. Such intrinsic in situ doping by a solid solution includes at least one of interstitial solid solution and substitutional solid solution, and furthermore, such intrinsic in situ doping by a solid solution is mainly substitutional solid solution, i.e., the doped E atoms substitute for predetermined atoms in the lattice of sodium / potassium titanate or titanate.

[0117] The above in-situ intrinsic embedding means that E nanoparticles or oxidized E nanoparticles are embedded and dispersed in a sodium / potassium titanate or titanate matrix by in-situ embedding; that is, E nanoparticles or oxidized E nanoparticles are formed in situ by being partially or completely encapsulated by a sodium / potassium titanate or titanate matrix, without relying on external addition or mixing to embed them therein. The in-situ embedded E nanoparticles or oxidized E nanoparticles produced cannot move freely in the sodium / potassium titanate or titanate matrix and are not easily detached. Such in-situ intrinsic embedding is achieved by the simultaneous formation of E nanoparticles or oxidized E nanoparticles with the sodium / potassium titanate or titanate matrix during the hydrogen deposition / de-T reaction.

[0118] When E atoms or atomic clusters are intrinsically embedded in sodium / potassium titanate or titanate intermediate powder products in situ, the circumstances of intrinsic embedding in situ are the same.

[0119] Generally, the basic method of intrinsically doping with element E in situ is related to the solid solubility of element E in sodium / potassium titanate or titanate matrices. When the solid solubility of element E in sodium / potassium titanate or titanate matrices is high, intrinsically doping in situ occurs mainly in the form of E atoms or atomic clusters. When the solid solubility of element E in sodium / potassium titanate or titanate matrices is low, intrinsically doping in situ occurs mainly in the form of E nanoparticles or oxidized E nanoparticles.

[0120] Furthermore, the basic method for in-situ endogenous doping with element E is C E / C Ti This is also related to C E / C Ti If the value is low, doping occurs intrinsically in situ, mainly in the form of E atoms or atomic clusters, and C E / C Ti If the value is low or high, intrinsic doping occurs in situ, mainly in the form of E nanoparticles or oxidized E nanoparticles.

[0121] Furthermore, the element E mainly consists of at least one of Au, Pt, Pd, Ru, Rh, Re, Os, and Ir.

[0122] Furthermore, 0.03 <C E / C Ti For values ​​≤0.30, element E is mainly embedded intrinsically in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles, with a particle size of 2 nm to 20 nm.

[0123] 0.01 <C E / C TiFor values ​​≤0.03, element E is intrinsically embedded in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles and E atoms or atomic clusters.

[0124] 0 <C E / C Ti For values ​​≤0.01, element E is primarily embedded in the sodium / potassium titanate or titanate intermediate powder product in situ, in the form of E atoms or atomic clusters.

[0125] Furthermore, element E mainly consists of Cu, Fe, Ni, and at least one of Co.

[0126] Furthermore, 0.05 <C E / C Ti For values ​​≤0.30, element E is mainly embedded intrinsically in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles or oxidized E nanoparticles, with the particle size of the E nanoparticles being 2 nm to 20 nm.

[0127] 0.02 <C E / C Ti For values ​​≤0.05, element E is intrinsically embedded in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles or oxidized E nanoparticles and E atoms or atomic clusters.

[0128] 0 <C E / C Ti For values ​​≤0.02, element E is primarily doped in-situ into sodium / potassium titanate or titanate intermediate powder products in the form of E atoms or atomic clusters.

[0129] Furthermore, element E mainly contains Ag.

[0130] Furthermore, 0.20 <C E / C TiFor values ​​≤0.30, element E is mainly embedded intrinsically in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles, with a particle size of 2 nm to 20 nm.

[0131] 0.10 <C E / C Ti For values ​​≤0.20, element E is intrinsically embedded in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles and E atoms or atomic clusters.

[0132] 0 <C E / C Ti For values ​​≤0.10, element E is primarily doped in-situ into sodium / potassium titanate or titanate intermediate powder products in the form of E atoms or atomic clusters.

[0133] Furthermore, element E mainly consists of at least one of Zr and Hf.

[0134] And, 0 <C E / C Ti For values ​​≤0.30, element E is primarily doped in-situ into sodium / potassium titanate or titanate intermediate powder products in the form of E atoms or atomic clusters.

[0135] Preferably, 0 <C E / C Ti For values ​​≤0.10, element E is intrinsically doped in situ into the sodium / potassium titanate or titanate intermediate powder product in the form of E atoms or atomic clusters.

[0136] Because Ti, Zr, and Hf belong to the same group in the periodic table and have similar properties, Zr and Hf can be doped into sodium titanate / potassium titanate or titanate at high concentrations.

[0137] Furthermore, the element E mainly consists of at least one of Cr, V, Nb, Ta, W, and Mo.

[0138] Furthermore, 0.20 <C E / C Ti For values ​​≤0.30, element E is intrinsically embedded in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles or oxidized E nanoparticles, and E atoms or atomic clusters.

[0139] 0 <C E / C Ti For values ​​≤0.20, element E is intrinsically doped in-situ into the sodium / potassium titanate or titanate intermediate powder product in the form of E atoms or atomic clusters.

[0140] Preferably, 0 <C E / C Ti For values ​​≤0.10, element E is primarily doped in-situ into sodium / potassium titanate or titanate intermediate powder products in the form of E atoms or atomic clusters.

[0141] Since Ti has similar properties to Cr, V, Nb, Ta, W, and Mo, Cr, V, Nb, Ta, W, and Mo can be doped in relatively high concentrations into sodium / potassium titanate or titanic acid.

[0142] Furthermore, element E mainly consists of Mn, Sn, Pb, Bi, B, Be, and at least one of RE.

[0143] Furthermore, 0.10 <C E / C Ti For values ​​≤0.30, element E is mainly embedded intrinsically in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles or oxidized E nanoparticles, with the particle size of the E nanoparticles being 2 nm to 20 nm.

[0144] 0.06 <C E / C TiFor ≤0.10, element E is intrinsically embedded in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles or oxidized E nanoparticles, and E atoms or atomic clusters.

[0145] 0 <C E / C Ti For values ​​≤0.06, element E is intrinsically doped in-situ into the sodium / potassium titanate or titanate intermediate powder product in the form of E atoms or atomic clusters.

[0146] Preferably, 0 <C E / C Ti For values ​​≤0.03, element E is primarily doped in-situ into sodium / potassium titanate or titanate intermediate powder products in the form of E atoms or atomic clusters.

[0147] The following points should be added.

[0148] The above terms "sodium titanate / potassium titanate" refer to "sodium titanate or / or potassium titanate," and may also be written as "at least one of sodium titanate and potassium titanate." Furthermore, it may be written as sodium titanate (potassium), in which potassium is dissolved in sodium titanate, or potassium titanate (sodium), in which sodium is dissolved in potassium titanate.

[0149] The above NaOH / KOH represents NaOH or / or KOH, and can also be written as at least one of NaOH or KOH.

[0150] In step 3 above,

[0151] Ba 2+ / Li + is "Ba 2+ or (and) Li + This represents "Ba 2+ and Li + It is also written as "at least one of the following."

[0152] The above-mentioned Ba 2+ / Li + The barium / lithium source material containing is at least one of a base containing Ba 2+ / Li + and a salt containing Ba 2+ / Li + and contains at least one of the following:

[0153] Furthermore, the base containing the above-mentioned Ba 2+ / Li + contains at least one of Ba(OH)2 and LiOH.

[0154] Furthermore, the base containing the above-mentioned Ba 2+ / Li + mainly contains Ba 2+ and is mainly composed of Ba(OH)2.

[0155] Furthermore, the base containing the above-mentioned Ba 2+ / Li + mainly contains Li + and is mainly composed of LiOH.

[0156] Furthermore, the salt containing the above-mentioned Ba 2+ / Li + contains at least one of water-soluble BaCl2, LiCl, Ba(NO3)2, LiNO3, and Li2SO4.

[0157] Furthermore, the salt containing the above-mentioned Ba 2+ / Li + contains at least one of poorly water-soluble Li3PO4, Ba3(PO4)2, Li2CO3, BaCO3, BaSO4, and BaS.

[0158] Furthermore, when the above-mentioned medium atmosphere is a solution, the barium / lithium source material containing the above-mentioned Ba 2 + / Li + is mainly a water-soluble salt or base and contains at least one of Ba(OH)2, LiOH, BaCl2, LiCl, Ba(NO3)2, LiNO3, and Li2SO4.

[0159] Furthermore, if the above media atmosphere is a solution, then the above Ba 2 + / Li + Barium / lithium source materials containing this mainly consist of at least one of water-soluble Ba(OH)2 and LiOH.

[0160] Furthermore, if the above media atmosphere is non-solution, step 3 is specifically as follows: The intermediate powder product from step 2 is Ba 2 + / Li + A barium / lithium source material containing the barium is mixed with ball mill grinding and sand mill grinding, and a solid-phase reaction is carried out, in which the Ba in the reaction system 2+ / Li + The ratio of the molar content of to the molar content of Ti in the intermediate powder product is in the range of 0.75:1 to 1.25:1. After the reaction is complete, the product is ground and dispersed by ball milling or sand milling to obtain a nanobarium titanate / lithium particle powder product in which element E is intrinsically doped in situ.

[0161] Furthermore, if the above media atmosphere is non-solution, then the above Ba 2+ / Li + Barium / lithium source materials mainly consist of at least one of the poorly water-soluble Li3PO4, Ba3(PO4)2, Li2CO3, BaCO3, BaSO4, and BaS.

[0162] Furthermore, if the above media atmosphere is non-solution, then the above Ba 2+ / Li + Barium / lithium source materials mainly consist of at least one of the poorly water-soluble Li3PO4, Ba3(PO4)2, Li2CO3, BaCO3, BaSO4, and BaS.

[0163] Furthermore, if the above media atmosphere is non-solution, then the above Ba 2+ / Li + Barium / lithium source materials containing this mainly consist of at least one of poorly water-soluble Li2CO3 and BaCO3.

[0164] Furthermore, when the above-mentioned media atmosphere is non-solution, the temperature of the solid-phase reaction is 400°C to 1500°C.

[0165] Furthermore, when the above-mentioned media atmosphere is non-solution, the temperature of the solid-phase reaction is 400°C to 1300°C.

[0166] Furthermore, when the above-mentioned media atmosphere is non-solution, the temperature of the solid-phase reaction is 600°C to 1000°C.

[0167] Furthermore, if the above medium atmosphere is a solution, the above non-spherical intermediate powder product is Ba 2+ / Li + Morphological changes and cation substitution reactions involving "spheroidization" by water-soluble salts or bases containing the following primarily manifest in the following ways.

[0168] During the reaction process, the sodium / potassium titanate or titanic acid is replaced with barium / lithium titanate.

[0169] During the reaction process, the shape of the above-mentioned sodium / potassium nanotitanate or titanate thin film powder intermediate product "spheroidizes," changing into spherical or nearly spherical particles with an average particle size of 5 nm to 300 nm.

[0170] During the reaction process, the shape of the above nanoporous sodium / potassium titanate or titanate irregular powder intermediate product "spheroidizes," changing into spherical or nearly spherical particles with an average particle size of 5 nm to 300 nm.

[0171] During the reaction process, the shape of the nano-sodium titanate / potassium tube (rod) or titanate tube (rod) powder intermediate product changes from a tubular (rod) shape to a "spheroidal" shape, transforming into spherical or nearly spherical particles with an average particle size of 5 nm to 300 nm.

[0172] During the reaction process, the in-situ endogenously doped element E in the intermediate powder product maintains its in-situ endogenously doped state.

[0173] In the reaction process, the process of substituting the above-mentioned sodium / potassium nanotitanate or titanic acid with barium / lithium nanotitanate is not slower than the process of "spheroidization" of the non-spherical intermediate powder product. That is, the substitution reaction and "spheroidization" start simultaneously, but the substitution reaction process may be completed first, and the "spheroidization" of the non-spherical intermediate powder product may continue after the substitution reaction is complete.

[0174] Furthermore, the spherical or substantially spherical particles include at least one of solid spherical or substantially spherical particles and non-solid spherical or substantially spherical particles.

[0175] Furthermore, the non-solid spherical or nearly spherical particles include at least one hollow spherical or nearly spherical particle and at least one partially hollow spherical or nearly spherical particle.

[0176] Furthermore, hollow spherical or nearly spherical particles include hollow spherical shell particles.

[0177] Furthermore, partially hollow spherical or nearly spherical particles include incompletely hollow spherical shell particles.

[0178] Furthermore, the thickness of the spherical shell wall of the hollow or partially hollow spherical shell particles described above is 3 nm to 10 nm.

[0179] Furthermore, the minimum sintering temperature for spherical or nearly spherical barium titanate / lithium particle powder products in which the above-mentioned element E is intrinsically doped in situ does not exceed 950°C.

[0180] Furthermore, the minimum sintering temperature for spherical or nearly spherical barium titanate / lithium particle powder products in which the above-mentioned element E is intrinsically doped in situ does not exceed 850°C.

[0181] Furthermore, when the E element is in-situ and endogenously doped in sodium / potassium titanate nanowires or the types and contents of the E element in titanic acid are different, it will also affect the "spheroidization" process of the non-spherical intermediate powder product. Generally, the presence of the doped E element inhibits the "spheroidization" process to a certain extent, and the greater the content of the E element, the more significant the influence will be.

[0182] In the above reaction system, the conditions for the occurrence of "spheroidization" and cation substitution reaction in the non-spherical intermediate powder product are mainly as follows.

[0183] The medium atmosphere is mainly a solution medium, the pressure is normal pressure or above normal pressure, and the barium / lithium source substance is mainly Ba 2+ / Li + -containing water-soluble salt or base, the reaction temperature is 30°C - T f溶液媒体 and the reaction time is 5 s or more. Here, T f溶液媒体 is the boiling point temperature of the solution medium at normal pressure, and the value of T f溶液媒体 varies depending on the type and concentration of the water-soluble salt or base containing Ba 2+ / Li + and its general range is 100°C to 150°C.

[0184] Furthermore, the pressure is normal pressure, that is, the reaction is carried out in an open container.

[0185] Furthermore, the above barium / lithium source substance contains at least one of Ba(OH)2, LiOH, BaCl2, LiCl, Ba(NO3)2, LiNO3, and Li2SO4.

[0186] Furthermore, the above barium / lithium source substance contains at least one of Ba(OH)2 and LiOH.

[0187] Furthermore, in the above reaction system, the total molar content C 2+ of Ba + / Li Ba / Li in the aqueous solution and the molar content C of Ti in the sodium / potassium titanate nanowires or titanic acid powderTi Ratio C Ba / Li / C Ti 0.8 ≤ C Ba / Li / C Ti It satisfies the condition.

[0188] Furthermore, 1 ≤ C Ba / Li / C Ti Furthermore, 1 ≤ C Ba / Li / C Ti The value is ≤ 10.

[0189] Furthermore, the reaction temperature is 50°C-T f溶液媒体 That is the case.

[0190] Furthermore, the reaction temperature is 80°C-T f溶液媒体 Furthermore, the reaction temperature is 100℃-T f溶液媒体 That is the case.

[0191] Furthermore, the reaction time is 10 seconds to 10 hours, and even further, the reaction time is 10 seconds to 1 hour.

[0192] Furthermore, the reaction temperature is T f溶液媒体 In that case, the reaction time is 10 seconds to 15 minutes.

[0193] Furthermore, the reaction temperature is T f溶液媒体 In that case, the reaction time is 10 seconds to 5 minutes.

[0194] Furthermore, the reaction temperature is T f溶液媒体 In that case, the reaction time is 10 seconds to 2 minutes.

[0195] Preferably, when the aqueous solution in the reaction system contains a NaOH / KOH component, the reaction effect is higher, and in this case, the NaOH / KOH component has a catalytic effect.

[0196] Preferably, the total concentration of NaOH / KOH in the aqueous solution is 0.001 mol / L to 25 mol / L.

[0197] Preferably, the total concentration of NaOH / KOH in the aqueous solution is 0.001 mol / L to 1 mol / L.

[0198] Furthermore, if a subsequent dry heat treatment is necessary to further promote spheroidization, the temperature of the subsequent dry heat treatment is 150°C to 1300°C.

[0199] Furthermore, if a subsequent dry heat treatment is necessary to further promote spheroidization, the temperature of the subsequent dry heat treatment is 150°C to 1000°C.

[0200] During the reaction, the sodium / potassium nanotitanate is replaced with barium / lithium nanotitanate, or the nanotitanium acid is replaced with barium / lithium nanotitanate.

[0201] If the above non-spherical intermediate powder product is an intermediate product of sodium / potassium nanotitanate or titanate thin film powder mainly intrinsically doped with element E in situ, then its primary "spheroidization" process and mechanism are as follows.

[0202] In the reaction system solution, if a sodium / potassium nanotitanate or titanate thin film intrinsically doped with element E in situ is a single free film, the sodium / potassium nanotitanate or titanate is replaced by barium / lithium nanotitanate. Simultaneously, after the replacement, the thin film undergoes a spherical shrinkage process to become a single spherical or nearly spherical particle. If the primary "spheroidization" is incomplete, shrinkage of the thin film yields non-solid spherical or nearly spherical shell particles with an outer diameter range of 5 nm to 150 nm. If "spheroidization" is complete, depending on the size of the original thin film, the non-solid spherical or nearly spherical shell particles further condense to become nearly solid spherical or nearly spherical particles with a particle size range of 2 nm to 30 nm, and further to 2 nm to 20 nm.

[0203] Therefore, in the case of a single free nanonano sodium / potassium titanate or titanate thin film, its spheroidization process can be broadly summarized as thin film state → non-solid spherical shell state → solid spherical state.

[0204] Furthermore, the spherical or substantially spherical particles include at least one of solid spherical or substantially spherical particles and non-solid spherical or substantially spherical particles.

[0205] Furthermore, the non-solid spherical or substantially spherical particles include at least one of non-solid spherical or substantially spherical shell particles and non-solid spherical or substantially spherical shell particles having an incomplete shell.

[0206] Furthermore, the thickness of the spherical shell wall of the non-solid spherical or substantially spherical shell particles is 2 nm to 10 nm.

[0207] In the reaction system solution, when the nano-sodium / potassium titanate or titanic acid thin film in which element E is in-situ and endogenously doped is an aggregate in which the thin films are intertwined, the spheroidization and shrinkage process of a single thin film is hindered by the spheroidization and shrinkage processes of other intertwined thin films, and the free spheroidization process of "thin film state → non-solid spherical shell state → solid spherical" is restricted. Multiple adjacent thin films fuse and shrink to form a non-free "spheroidized" unit of larger barium / lithium titanate. Multiple or numerous non-free "spheroidized" units further aggregate, and a larger aggregate is formed by the binding force between the soft aggregate and the hard aggregate. The aggregate has structural characteristics similar to a nanoporous structure, and the non-free "spheroidized" unit is similar to the ligament of the nanoporous structure.

[0208] When the non-spherical intermediate powder product is mainly an intermediate product of nano-porous sodium / potassium titanate or irregular titanic acid powder in which element E is in-situ and endogenously doped, its primary "spheroidization" process and mechanism are as follows.

[0209] Nanoporous sodium / potassium titanate or titanate disordered powder particles, intrinsically doped with element E in situ, are generally large in size, but possess a three-dimensional continuous network nanoporous structure internally. The average diameter of ligaments in the nanoporous sodium / potassium titanate or titanate microstructure is less than 10 nm, and even less than 5 nm, resulting in an extremely high specific surface area. Therefore, when porous ligaments in nanoporous sodium / potassium titanate or titanate disordered powder intermediates are replaced with nanobarium / lithium titanate, many ligaments may also undergo a shrinkage "spheroidization" process. Multiple adjacent nanoporous ligaments shrink and spheroidize, forming larger non-free "spheroidized" units of nanobarium / lithium titanate. Multiple or many non-free "spheroidized" units further aggregate, and due to the bonding force between the soft aggregates and hard aggregates, larger aggregates are formed. These aggregates have structural characteristics similar to the nanoporous structure, and the non-free "spheroidized" units are similar to the ligaments of the nanoporous structure.

[0210] If the above non-spherical intermediate powder product is mainly a sodium / potassium nanotitanate or titanate tube (rod) intermediate product in which element E is endogenously doped in situ, then its primary "spheroidization" process and mechanism are as follows:

[0211] In the reaction system solution, if a single free tube (rod) is intrinsically doped with element E in situ using sodium / potassium nanotitanate or titanate, the sodium / potassium nanotitanate or titanate is replaced by barium / lithium nanotitanate. Simultaneously, after the replacement, the tube (rod) undergoes a spherical contraction process to form a single spherical or nearly spherical particle. Due to the limited size and volume of the original single tube (rod), the particle size of the single spherical or nearly spherical particle typically does not exceed 30 nm. Furthermore, depending on the size of the original tube (rod), the particle size range of the single spherical or nearly spherical particle is 3 nm to 30 nm, and furthermore, the particle size range of the single spherical or nearly spherical particle is 3 nm to 20 nm.

[0212] In the reaction system solution, if element E is an entangled aggregate of in-situ intrinsically doped sodium / potassium nanotitanate or titanate tubes (rods), the spheroidization and shrinkage process of a single tube (rod) is hindered by the spheroidization and shrinkage processes of other entangled tubes (rods), causing multiple adjacent tubes (rods) to fuse and shrink, forming larger non-free "spheroidized" units of barium / lithium nanotitanate. Multiple or numerous non-free "spheroidized" units further aggregate, and due to the bonding forces between the soft and hard aggregates, larger aggregates are formed, which have structural features similar to nanoporous structures, and the non-free "spheroidized" units are similar to ligaments in nanoporous structures.

[0213] The primary "spheroidization" process and mechanism of the three different non-spherical intermediate powder products described above are as follows.

[0214] Furthermore, the composition of the above non-free "spheroidized" units is mainly barium / lithium nanotitanium intrinsically doped with element E in situ.

[0215] Furthermore, the shape of the above non-free "spheroidized" nanobarium / lithium titanate units is between an imperfect solid sphere and a short rod. It can be seen that the degree of spheroidization is influenced by the entanglement of different thin films or different tubes (rods) during the formation process of the non-free "spheroidized" nanobarium / lithium titanate units, and the shape is between a sphere and a short rod.

[0216] Furthermore, the above-mentioned barium / lithium nanotitanium non-free "spheroidized" unit is in a metastable state.

[0217] Furthermore, the average diameter range of the non-free "spheroidized" nanobarium / lithium titanate units in which the above-mentioned element E is intrinsically doped in situ is 5 nm to 300 nm, furthermore, the average diameter range of the non-free "spheroidized" nanobarium / lithium titanate units in which the above-mentioned element E is intrinsically doped in situ is 5 nm to 250 nm, furthermore, the average diameter range of the non-free "spheroidized" nanobarium / lithium titanate units in which the above-mentioned element E is intrinsically doped in situ is 5 nm to 200 nm, and furthermore, the average diameter range of the non-free "spheroidized" nanobarium / lithium titanate units in which the above-mentioned element E is intrinsically doped in situ is 5 nm to 100 nm.

[0218] Furthermore, the average particle size range of the aggregates is 50 nm to 5 μm, furthermore, the average particle size range of the aggregates is 50 nm to 2 μm, and furthermore, the average particle size range of the aggregates is 50 nm to 1 μm.

[0219] Furthermore, by subsequently dispersing the aggregates through mechanical grinding and dispersion treatment, a spherical or nearly spherical powder product of barium / lithium nanotitanate, intrinsically doped with element E in situ, can be obtained, using the original non-free "spheroidized" nanotitanate barium / lithium units as the basic particle units.

[0220] Furthermore, using non-free "spheroidized" nanobarium / lithium titanate units as the basic particle units, the minimum sintering temperature for spherical or nearly spherical nanobarium / lithium titanate powder products in which element E is intrinsically doped in situ does not exceed 950°C.

[0221] Furthermore, using non-free "spheroidized" nanobarium titanate / lithium "spheroidized" units as the basic particle units, the minimum sintering temperature for spherical or nearly spherical nanobarium titanate / lithium powder products in which element E is intrinsically doped in situ does not exceed 850°C.

[0222] The non-free "spheroidized" units of nanobarium / lithium titanate have small particle sizes, and most are not completely solidified into spheroids. However, they still have a high specific surface area and possess metastable and high-energy properties, resulting in a low minimum sintering temperature at which the particles locally melt to form a thin film.

[0223] The three typical non-spherical intermediate powder products described above undergo primary "spheroidization" during the cation substitution reaction. If the cation substitution reaction is complete but primary "spheroidization" is insufficient, increasing the temperature / pressure of the solution, increasing the NaOH / KOH concentration in the solution, extending the reaction time, or further dry-heat treatment of the primary spheroidized product can yield more complete spheroidization and spherical or nearly spherical barium titanate / lithium nanoparticle powder products intrinsically doped with element E in situ.

[0224] Furthermore, if the primary "spheroidization" in step 3 is insufficient, the degree of "spheroidization" can be improved by at least one of the following three methods.

[0225] (1) By placing the reaction system in a sealed container and treating it at high temperature and high pressure for a certain period of time, the non-free "spheroidized" units can be further contracted to produce spherical or nearly spherical barium titanate / lithium nanoparticles with high solidity and intrinsically doped with element E in situ. The above temperature is 150°C to 300°C, and the above pressure is the pressure inside the sealed container at this temperature.

[0226] (2) The solution in the reaction system is continuously evaporated to dryness, and the residual solids are heated to 150°C to 400°C without changing the reaction vessel, and the temperature is maintained for a certain period of time. By processing at this temperature, the non-free "spheroidized" units are further contracted, and spherical or nearly spherical barium titanate / lithium nanoparticles with high solidity and intrinsically doped with element E in situ can be obtained.

[0227] (3) The solid material in the reaction system is collected and heated to 150°C to 1300°C, and then kept warm for a certain period of time. This temperature, especially the high-temperature treatment (600°C to 1300°C), further shrinks the non-free "spheroidized" units, resulting in spherical or nearly spherical particles with very high solidity. However, during the high-temperature treatment (600°C to 1300°C), the non-free "spheroidized" units first shrink into spherical or nearly spherical barium / lithium nanotitanate particles with very high solidity, and after they have almost completely solidified, further high-temperature treatment causes sintering and aggregation of the spherical or nearly spherical particles with very high solidity. Therefore, in order to obtain spherical or nearly spherical barium / lithium nanotitanate particles intrinsically doped with element E in situ without obvious sintering or aggregation, it is necessary to appropriately control the heat treatment temperature and time.

[0228] Furthermore, after the above processing, by mechanically grinding and dispersing the spherical or approximately spherical barium / lithium nanotitanate particles, a completely solidified spherical or approximately spherical barium / lithium nanotitanate powder product can be obtained, which is intrinsically doped with element E in situ.

[0229] Furthermore, in the process in which a sodium / potassium nanotitanate or titanate matrix intrinsically doped with element E in situ is converted to a barium / lithium nanotitanate matrix by reaction, the intrinsically doped element E is present in the solid material both before and after the reaction and cannot be removed. Therefore, the element E remains intrinsically doped in situ into the newly generated barium / lithium nanotitanate matrix, resulting in barium / lithium nanotitanate particles intrinsically doped with element E in situ.

[0230] Furthermore, the element E mainly consists of at least one of Au, Pt, Pd, Ru, Rh, Re, Os, and Ir.

[0231] Furthermore, 0.03 <C E / C TiFor values ​​≤0.30, element E is mainly embedded intrinsically in the barium titanate / lithium powder product in the form of E nanoparticles, with a particle size of 2 nm to 20 nm.

[0232] 0.01 <C E / C Ti For values ​​≤0.03, element E is intrinsically embedded in the barium titanate / lithium powder product in the form of E nanoparticles and E atoms or atomic clusters.

[0233] 0 <C E / C Ti For values ​​≤0.01, element E is primarily embedded intrinsically in barium titanate / lithium powder products in the form of E atoms or atomic clusters.

[0234] Furthermore, element E mainly consists of Cu, Fe, Ni, and at least one of Co.

[0235] Furthermore, 0.05 <C E / C Ti For values ​​≤0.30, element E is mainly embedded intrinsically in the barium titanate / lithium powder product in the form of E nanoparticles or oxide E nanoparticles, with the particle size of the E nanoparticles being 2 nm to 20 nm.

[0236] 0.02 <C E / C Ti For values ​​≤0.05, element E is intrinsically embedded in the barium titanate / lithium powder product in the form of E nanoparticles or oxide E nanoparticles and E atoms or atomic clusters.

[0237] 0 <C E / C Ti For values ​​≤0.02, element E is primarily doped in-situ into the barium titanate / lithium powder product in the form of E atoms or atomic clusters.

[0238] Furthermore, element E mainly contains Ag.

[0239] Furthermore, 0.20 <C E / C Ti For values ​​≤0.30, element E is mainly embedded intrinsically in the barium titanate / lithium powder product in the form of E nanoparticles, with a particle size of 2 nm to 20 nm.

[0240] 0.10 <C E / C Ti For values ​​≤0.20, element E is intrinsically embedded in the barium titanate / lithium powder product in the form of E nanoparticles and E atoms or atomic clusters.

[0241] 0 <C E / C Ti For values ​​≤0.10, element E is primarily doped in-situ into the barium titanate / lithium powder product in the form of E atoms or atomic clusters.

[0242] Furthermore, element E mainly consists of at least one of Zr and Hf.

[0243] And, 0 <C E / C Ti For values ​​≤0.30, element E is primarily doped in-situ into the barium titanate / lithium powder product in the form of E atoms or atomic clusters.

[0244] Preferably, 0 <C E / C Ti For values ​​≤0.10, element E is intrinsically doped in the barium titanate / lithium powder product in the form of E atoms or atomic clusters.

[0245] Because Ti, Zr, and Hf belong to the same group in the periodic table and have similar properties, barium titanate / lithium can be doped with high concentrations of Zr and Hf.

[0246] Furthermore, the element E mainly consists of at least one of Cr, V, Nb, Ta, W, and Mo.

[0247] Furthermore, 0.20 <CE / C Ti For values ​​≤0.30, element E is intrinsically embedded in the barium titanate / lithium powder product in the form of E nanoparticles or oxidized E nanoparticles, and E atoms or atomic clusters.

[0248] 0 <C E / C Ti For values ​​≤0.20, element E is intrinsically doped in the barium titanate / lithium powder product in the form of E atoms or atomic clusters.

[0249] Preferably, 0 <C E / C Ti For values ​​≤0.10, element E is primarily doped in-situ into the barium titanate / lithium powder product in the form of E atoms or atomic clusters.

[0250] Since Ti has similar properties to Cr, V, Nb, Ta, W, and Mo, Cr, V, Nb, Ta, W, and Mo can be doped into barium titanate / lithium in relatively high concentrations.

[0251] Furthermore, element E mainly consists of Mn, Sn, Pb, Bi, B, Be, and at least one of RE.

[0252] Furthermore, 0.10 <C E / C Ti For values ​​≤0.30, element E is mainly embedded intrinsically in the barium titanate / lithium powder product in the form of E nanoparticles or oxide E nanoparticles, with the particle size of the E nanoparticles being 2 nm to 20 nm.

[0253] 0.06 <C E / C Ti For ≤0.10, element E is intrinsically embedded in the barium titanate / lithium powder product in the form of E nanoparticles or oxide E nanoparticles, and E atoms or atomic clusters.

[0254] 0 <C E / C TiFor values ​​≤0.06, element E is intrinsically doped in the barium titanate / lithium powder product in the form of E atoms or atomic clusters.

[0255] Preferably, 0 <C E / C Ti For values ​​≤0.03, element E is primarily doped in-situ into the barium titanate / lithium powder product in the form of E atoms or atomic clusters.

[0256] C E / C Ti If = 0, the doped E element content is 0, and the manufactured product is a barium titanate / lithium powder product.

[0257] In particular, as an optimized wet one-pot method solution, if the composition of the intermediate powder product obtained in step 2 mainly contains sodium / potassium nanotitanate intrinsically doped with element E in situ, combining steps 2 and 3 can achieve the production of barium / lithium nanotitanate particle powder products intrinsically doped with element E in situ by a one-pot method.

[0258] The one-pot method, which combines steps 2 and 3, includes the following two methods:

[0259] Method 1 is to perform Ba after the completion of step 2. 2+ / Li + Barium / lithium source material containing or Ba 2+ / Li + The barium / lithium source solution containing the specified substance is added to the reaction system in step 2, and the reaction is continued at a constant temperature for a certain period of time.

[0260] For specific information regarding Step 2, please refer to the detailed explanation of Step 2 above.

[0261] Furthermore, the above barium / lithium source material includes at least one of Ba(OH)2, LiOH, BaCl2, LiCl, Ba(NO3)2, LiNO3, and Li2SO4.

[0262] Furthermore, the above barium / lithium source material includes at least one of Ba(OH)2 and LiOH.

[0263] Furthermore, in the reaction system after adding the above barium / lithium source material, the Ba in aqueous solution 2+ / Li + Total molar content C Ba / Li And the molar content of Ti in sodium / potassium nanotitanate or titanate powder C Ti Ratio C Ba / Li / C Ti 0.8 ≤ C Ba / Li / C Ti It satisfies the condition.

[0264] Furthermore, 1 ≤ C Ba / Li / C Ti Furthermore, 1 ≤ C Ba / Li / C Ti The value is ≤ 10.

[0265] Furthermore, the continuous reaction temperature is 50°C-T f溶液媒体 That is the case.

[0266] Furthermore, the continuous reaction temperature is 80°C-T f溶液媒体 Furthermore, the continuous reaction temperature is 100°C-T f溶液媒体 That is the case.

[0267] Furthermore, the duration of the reaction was 10 seconds to 10 hours, and even further, the duration of the reaction was 10 seconds to 1 hour.

[0268] Furthermore, the continuous reaction temperature is T f溶液媒体 In that case, the duration of the reaction is 10 seconds to 15 minutes.

[0269] Furthermore, the continuous reaction temperature is T f溶液媒体 In that case, the duration of the reaction is 10 seconds to 5 minutes.

[0270] Furthermore, the reaction temperature is T f溶液媒体 In that case, the reaction time is 10 seconds to 2 minutes.

[0271] In this reaction system, the reaction is efficient because the solution contains a sufficient amount of NaOH / KOH.

[0272] Method 2 is as follows: At the start of step 2, Ba 2+ / Li + An appropriate amount of barium / lithium source material containing [the specified substance] is added to the reaction solution system along with NaOH / KOH, and the reaction is carried out at a constant temperature for a certain period of time.

[0273] This invention has found that, during the hydrogen deposition and de-T reaction of the initial alloy in step 2, if the base solution mainly consists of Ba(OH)2 or / and / LiOH, under normal pressure, even when the concentration of the Ba(OH)2 or / and / LiOH solution reaches its highest concentration (10 mol / L or more) at its boiling point and the temperature reaches the boiling point of the solution (105°C to 130°C), the initial alloy still has difficulty reacting with the Ba(OH)2 or / and / LiOH solution to undergo the hydrogen deposition and de-T reaction, and remains almost in its original alloy state. Therefore, it is not possible to directly produce barium titanate / lithium nanotitanate by reacting the initial alloy with an aqueous solution of Ba(OH)2 or / and / LiOH to induce a hydrogen deposition and de-T reaction. Instead, it is necessary to produce barium titanate / lithium titanate by reacting it with NaOH / KOH via the pathway "initial alloy → sodium titanate / potassium titanate → barium titanate / lithium titanate".

[0274] Therefore, in the second one-pot method, the reaction solution system must first have a sufficient effective concentration of NaOH / KOH to achieve the conversion from the initial alloy to sodium / potassium titanate. At the same time, the Ba in the reaction solution system 2+ / Li + The concentration should not be too high in order to ensure the conversion from sodium titanate / potassium titanate to barium titanate / lithium titanate; a moderate amount is sufficient. Otherwise, Ba 2+ / Li +If the concentration is too high, it will affect the conversion from the initial alloy to sodium titanate / potassium titanate, and also, excess Ba 2+ / Li + It will be wasted.

[0275] Furthermore, the above barium / lithium source material includes at least one of Ba(OH)2, LiOH, BaCl2, LiCl, Ba(NO3)2, LiNO3, and Li2SO4.

[0276] Specifically, in the above base solution,

[0277] If the total concentration range of NaOH / KOH is 5 mol / L to 7.5 mol / L, 2+ / Li + The corresponding total concentration is 2.0 mol / L or less.

[0278] If the total concentration range of NaOH / KOH is 7.5 mol / L to 10 mol / L, 2+ / Li + The corresponding total concentration is 3.5 mol / L or less.

[0279] If the total concentration range of NaOH / KOH is 10 mol / L to 15 mol / L, 2+ / Li + The corresponding total concentration is 5 mol / L or less.

[0280] If the total concentration range of NaOH / KOH is 15 mol / L to 30 mol / L, 2+ / Li + The corresponding total concentration is 8 mol / L or less.

[0281] Furthermore, in order to more effectively achieve the conversion from "initial alloy → sodium titanate / potassium titanate → barium titanate / lithium", the total concentration of NaOH / KOH in the one-pot base solution should be in the range of 5 mol / L to 30 mol / L, preferably 7 mol / L to 15 mol / L, Ba 2+ / Li +The concentration should be as low as possible, provided that complete conversion from sodium / potassium titanate to barium / lithium titanate is ensured. Its specific value can be determined depending on the Ti content of the initial alloy in the reaction system.

[0282] Furthermore, the above Ba 2+ / Li + In the reaction system after adding the barium / lithium source material, the Ba in aqueous solution 2+ / Li + Total molar content C Ba / Li And the molar content of Ti in the initial alloy C Ti Ratio C Ba / Li / C Ti 0.8 ≤ C Ba / Li / C Ti It satisfies the condition.

[0283] Furthermore, 1 ≤ C Ba / Li / C Ti Furthermore, 1 ≤ C Ba / Li / C Ti ≤ 1.5, and furthermore, 1 ≤ C Ba / Li / C Ti The value is ≤ 3.

[0284] Furthermore, 1 ≤ C Ba / Li / C Ti The value is ≤ 10.

[0285] For specific information regarding Step 2, please refer to the detailed description of Step 2 above. For example, different forms of sodium titanate / potassium intermediate powder products can be obtained depending on the different specific reaction conditions 1) to 4) of Step 2 above.

[0286] 1) Under normal pressure, when the NaOH / KOH concentration is high and the temperature of the base solution is high, the intermediate powder product mainly consists of sodium / potassium nanotitanate thin film powder in which element E is endogenously doped in situ.

[0287] 2) Under normal pressure, with low NaOH / KOH concentrations and low temperatures of the base solution, the intermediate powder product mainly consists of nanoporous sodium / potassium titanate disordered powder in which element E is intrinsically doped in situ.

[0288] 3) Under normal pressure, with moderate NaOH / KOH concentrations and moderate temperatures of the base solution, the intermediate powder product mainly consists of nanoporous sodium / potassium titanate disordered powder in which element E is intrinsically doped in situ and nanoporous sodium / potassium titanate thin film powder intrinsically doped in situ.

[0289] 4) The reaction takes place in a sealed container at a pressure higher than atmospheric pressure, with a high concentration of NaOH / KOH, and at a temperature equal to the boiling point T at 1 atmosphere. f溶液 At temperatures higher than the target temperature, the intermediate powder product mainly contains sodium / potassium nanotitanate tubes (rods) intrinsically doped with element E in situ.

[0290] The one-pot method described above has the following characteristics.

[0291] Furthermore, the reaction temperature is 50°C-T f溶液媒体 That is the case.

[0292] Furthermore, the reaction temperature is 80°C-T f溶液媒体 Furthermore, the reaction temperature is 100℃-T f溶液媒体 That is the case.

[0293] Furthermore, the reaction time is 10 seconds to 10 hours, and even further, the reaction time is 10 seconds to 1 hour.

[0294] Furthermore, the reaction temperature is T f溶液媒体 In that case, the reaction time is 10 seconds to 15 minutes.

[0295] Furthermore, the reaction temperature is T f溶液媒体 In that case, the reaction time is 10 seconds to 5 minutes.

[0296] Furthermore, the reaction temperature is T f溶液媒体In that case, the reaction time is 10 seconds to 2 minutes.

[0297] In this reaction system, the solution contains a sufficient amount of NaOH / KOH components, and the solution contains C Ba / Li When the content is not high, the reaction effect is good.

[0298] Furthermore, to reduce the particle size of the in-situ doped barium titanate / lithium particle powder product with element E, it can be treated by at least one of the following three methods.

[0299] Method 1 is as follows: During the reaction process of step 2 or / or step 3, ultrasonic treatment is simultaneously applied to the reaction system. The ultrasonic frequency is 20 kHz to 10 6 The frequency is kHz. Ultrasonic treatment can grind the particle size of the intermediate powder product to a certain extent. This is particularly effective when the intermediate product is a nanoporous sodium / potassium titanate disordered powder intrinsically doped with element E in situ.

[0300] In Method 2, mechanical grinding and dispersion are performed after step 3, and the mechanical grinding and dispersion method includes at least one of ball milling and sand milling.

[0301] Furthermore, by mechanically dispersing the product, the aggregated E element intrinsically doped nanobarium titanate / lithium particles can be dispersed into even finer particles.

[0302] Furthermore, after mechanically dispersing the product, the average particle size range of the intrinsically doped barium titanate / lithium nanoparticles with element E is 10 nm to 250 nm.

[0303] In Method 3, after step 2, the intermediate powder product is mechanically ground and dispersed, and the mechanical grinding and dispersion process includes at least one of ball milling and sand milling.

[0304] The non-spherical intermediate powder product after step 2 is mainly at least one of the following: sodium / potassium nanotitanate thin film powder in-situ doped with element E, nanoporous sodium / potassium nanotitanate disordered powder in-situ doped with element E, and sodium / potassium nanotitanate tubes (rods) in-situ doped with element E. Compared to the mechanical dispersion treatment of spherical or nearly spherical barium / lithium nanotitanate products by method 2, the grinding process of non-spherical sodium / potassium nanotitanate thin films, nanoporous sodium / potassium nanotitanate disordered powder, and sodium / potassium nanotitanate tubes (rods) by method 3 exhibits a better restricted grinding state and achieves a more significant grinding and dispersion effect.

[0305] In the case of intermediate powder products of nanosodium titanate / potassium thin films, the thickness is typically less than 5 nm and the average area is 500 nm. 2 As a result, a single thin film can be easily pulverized by sand milling or ball milling, and the average area can be significantly reduced. For example, the average area of ​​a single thin film can be reduced to 1 / 10 or less of the original area. This allows the particle size range of the non-solid spherical or nearly spherical shell-like particles obtained in the subsequent "spheroidization" step 3 to be 5 nm to 50 nm or less, and the particle size of the nearly solid spherical or nearly spherical particles obtained through the polycondensation reaction can be 2 nm to 10 nm or less.

[0306] Because the area of ​​a single thin film is significantly reduced, and the size of non-free "spheroidized" units formed by the fusion and shrinkage of multiple adjacent small thin films is also significantly reduced, the average diameter range of spherical or nearly spherical barium / lithium nanotitanate particles, which are intrinsically doped in-situ with element E further obtained in step 3, after sand milling or ball milling, can be 5 nm to 150 nm or less.

[0307] Furthermore, after sand milling or ball milling, the average diameter range of spherical or nearly spherical barium / lithium nanotitanate particles, which are intrinsically doped in-situ with the element E further obtained in step 3, may be 5 nm to 100 nm or less.

[0308] The same mechanism also applies to nanoporous sodium / potassium titanate disordered powder intermediates, where, after sand milling or ball milling, the average diameter range of spherical or nearly spherical barium / lithium nanotitanate particles, further obtained in step 3 above and intrinsically doped with element E, can be 5 nm to 150 nm or less.

[0309] Furthermore, after sand milling or ball milling, the average diameter range of spherical or nearly spherical barium / lithium nanotitanate particles, which are intrinsically doped in-situ with the element E further obtained in step 3, may be 5 nm to 100 nm or less.

[0310] The same mechanism also applies to the sodium / potassium nanotitanate tube (rod) intermediate product, where, after sand milling or ball milling, the average diameter range of spherical or nearly spherical barium / lithium nanotitanate particles, further obtained in step 3 above and intrinsically doped with element E, may be 5 nm to 120 nm or less.

[0311] Furthermore, after sand milling or ball milling, the average diameter range of spherical or nearly spherical barium / lithium nanotitanate particles, which are intrinsically doped in-situ with the element E further obtained in step 3, may be 5 nm to 80 nm or less.

[0312] In actual operations, the three methods described above can be used simultaneously to obtain a nanobarium titanate / lithium particle powder product that is as fine as possible and intrinsically doped with element E in situ.

[0313] In a second embodiment, the present invention also relates to applications of an in-situ doped barium titanate / lithium powder material of element E produced by the manufacturing method described in the first embodiment in electronic ceramics, composite materials, coatings, powder metallurgy, multilayer ceramic capacitors, thermistors, piezoelectric ceramics, and battery materials.

[0314] Furthermore, the barium / lithium nanotitanate powder in which the above-mentioned element E is intrinsically doped in situ can be used as a compounding powder for multilayer ceramic capacitors (MLCCs), and the lithium nanotitanate powder intrinsically doped in situ with the above-mentioned element E can be used in the fields of lithium-ion batteries and asymmetric supercapacitors.

[0315] Specifically, the present invention has the following beneficial effects.

[0316] Firstly, by employing a novel doping method, we achieved in-situ intrinsic doping of doping elements into nanobarium titanate / lithium particle powder. Currently, the most effective methods for producing doped barium titanate particles are the hydrothermal method and the sol-gel method. In both methods, a gel or suspension containing a barium titanate precursor is first prepared, the doping target substance is added during this process, and then doped barium titanate is obtained by hydrothermal treatment or sintering. This two-step doping has certain characteristics of external doping, making it often difficult to obtain a homogeneous doping effect at the atomic scale. On the other hand, the present invention proposes a novel doping method in which doped E element is uniformly dispersed at the atomic scale in a T-Ti(E) intermetallic compound or a T-Ti-E intermetallic compound containing E element in a solid solution; then, by hydrogen deposition and de-T reaction of these intermetallic compounds containing E element, sodium / potassium nanotitanate intrinsically doped with E element in situ is obtained; and further, by cation substitution, barium / lithium nanotitanate intrinsically doped with E-type element in situ is obtained. E element is present in solid intermetallic compounds, sodium / potassium nanotitanate, and barium / lithium nanotitanate in that order, and is always present in solid materials. Since E element is not easily excreted from these solid materials, it remains intrinsically doped in-situ into newly generated barium / lithium nanotitanate matrices, resulting in barium / lithium nanotitanate particles intrinsically doped with E element in-situ. Depending on the doping content of E element, two basic doping methods can be obtained: "intrinsic doping in situ with E atoms or atomic clusters" and "intrinsic doping in situ with E nanoparticles or oxidized E nanoparticles." The core of this doping method is to first produce a T-Ti(E) intermetallic compound or a T-Ti-E intermetallic compound containing a certain amount of E element in solid solution. Generally, according to alloy phase diagrams, different E element atoms have different thermodynamic equilibrium solid solubility in T-Ti(E) intermetallic compounds.Even when the thermodynamic equilibrium solid solubility of element E in the T-Ti intermetallic compound is very low, it is possible to obtain a non-equilibrium solidification initial alloy by kinetic factors, i.e., by rapid solidification of the molten material. During the rapid solidification process, element E is not expelled from the T-Ti intermetallic compound in a timely manner, and as a result, a T-Ti(E) non-equilibrium intermetallic compound with significantly improved solid solubility is obtained. Therefore, if the cooling rate is sufficiently fast, theoretically, even if the equilibrium solid solubility is extremely low, most doping elements can be clearly dissolved in the T-Ti intermetallic compound. Based on this, the corresponding doped barium / lithium nanotitaniumate can be produced by the method of the present invention.

[0317] Secondly, we discovered and utilized the spheroidization mechanism in the process of obtaining nanobarium / lithium titanate by substitution reactions of sodium / potassium titanate or titanic acid. Through a non-spherical intermediate powder, we produced spherical or nearly spherical nanobarium / lithium titanate powder products in which element E is endogenously doped in-situ. Conventionally, powders obtained by hydrogen precipitation and de-T reactions of T-Ti(E) intermetallic compounds, or T-Ti-E intermetallic compounds containing element E, have been thin-film powders, irregular nanoporous powders, or tubular (rod) powders, lacking spherical or nearly spherical characteristics, thus severely limiting their application. In contrast, this invention, based on non-spherical sodium / potassium titanate or titanic acid intermediate powders, cleverly utilizes this novel principle to obtain spherical or nearly spherical nanobarium / lithium titanate products, which have significant application implications.

[0318] Third, the present invention can yield spherical or nearly spherical nanobarium / lithium titanate powder products having extremely fine particle sizes and intrinsically doped with element E in situ. Since the basic unit sizes (film thickness, porous band diameter, etc.) of sodium / potassium titanate or titanate thin film powder, sodium / potassium titanate or titanate irregular nanoporous powder, and sodium / potassium titanate or titanate tube (rod) powder are extremely small (less than 10 nm), barium / lithium titanate powder with a particle size of less than 30 nm can be produced from them as intermediate products. Even if the particle size of the non-free "spheroidized" units increases due to aggregation, the particle size of the intermediate powder before spheroidization can be reduced by pre-ball milling and sand milling of three representative non-spheroidal intermediate powders, and the particle size of the non-free "spheroidized" units after the substitution reaction can be reduced to less than 100 nm or even smaller. In the case of a single sodium / potassium titanate or titanate thin film, barium / lithium titanate powder with a particle size of less than 20 nm can also be obtained by physically subdividing it and then subjecting it to substitution treatment.

[0319] Fourth, spherical or nearly spherical powder products of barium / lithium nanotitanate intrinsically doped with element E in situ can be obtained in various forms. For example, according to the free spheroidization process mechanism of "thin film → non-solid spherical shell → solid sphere," if the "spheroidization" is insufficient, larger non-solid spherical or nearly spherical shell particles can be obtained. Further spheroidization treatment (such as heat treatment) can yield nearly solid spherical or nearly spherical product particles with even smaller particle sizes.

[0320] Fifth, the reaction conditions are simple and mild (high temperature and high pressure are not essential), making it suitable for large-scale and low-cost production. Generally, the product can be produced under atmospheric pressure and in a solution atmosphere at 100°C to 150°C. Furthermore, the initial alloy can be prepared using NaOH / KOH and Ba 2+ / Li + By directly adding it to a high-temperature base solution containing the substance using a one-pot method, the reaction can be completed in just a few minutes.

[0321] Sixth, the spherical or nearly spherical powder product of barium / lithium nanotitanate intrinsically doped with element E in situ has a low sintering film deposition temperature, making subsequent MLCC device manufacturing easier. The barium / lithium nanotitanate produced in this invention has a small particle size, can be controlled to be a non-perfect solid sphere, has a high specific surface area, metastable properties and high energy, so the minimum sintering temperature required for partial melting and film deposition can be kept low at 850°C to 950°C. In contrast, conventional processes require using barium nanotitanate powder at atmospheric pressure sintering and hot press sintering at temperatures of 1250°C and 1050°C, respectively, and holding the temperature for several hours. [Brief explanation of the drawing]

[0322] [Figure 1] Figure 1 shows the TEM morphology of the sodium nanotitanate thin film powder intermediate product obtained in Example 1.

[0323] [Figure 2] Figure 2 shows the low-magnification and high-magnification SEM morphology of the sodium nanotitanate powder product obtained in Example 1.

[0324] [Figure 3] Figure 3 shows the SEM morphology of the barium nanotitanate powder product obtained in Example 1 after treatment at 950°C.

[0325] [Figure 4] Figure 4 shows the SEM morphology of the barium nanotitanate powder product obtained in Example 3.

[0326] [Figure 5] Figure 5 shows the SEM morphology of the in-situ intrinsically doped barium titanate powder product obtained in Example 4.

[0327] [Figure 6] Figure 6 shows the SEM morphology of the barium titanate powder product obtained in Example 5, which was intrinsically doped with the rare earth element Nd in situ.

[0328] [Figure 7] Figure 7 shows the low-magnification and high-magnification SEM morphology of the nanoporous sodium titanate irregular coarse powder intermediate product obtained in Example 8.

[0329] [Figure 8] Figure 8 shows the SEM morphology of the barium nanotitanate powder obtained in Example 10 after heat treatment at 300°C.

[0330] [Figure 9] Figure 9 shows the SEM morphology of the barium nanotitanate powder obtained in Example 10 after heat treatment at 900°C.

[0331] [Modes for carrying out the invention]

[0332] [Example 1] Ti 25 Al 75 According to the nominal composition (atomic percentage), the Ti and Al raw materials are melted and Ti 25 Al 75 A molten alloy mainly composed of was obtained. The obtained molten alloy was fabricated into an initial alloy mainly composed of TiAl3 intermetallic compounds in ribbon-like form with a thickness of ~20 μm by copper roller strip casting.

[0333] Under normal pressure, the above-manufactured Ti 25 Al 75 Add 0.8g of initial alloy ribbon to 110ml of NaOH aqueous solution with a concentration of 10 mol / L and boiling point (approximately 119°C) while stirring, and Ti 25 Al 75 During the reaction with a concentrated base solution, the initial alloy ribbon was nanofragmented by a vigorous hydrogen deposition and de-algae reaction, while its shape and composition were simultaneously reconfigured, producing a nano-sodium titanate thin film powder intermediate product.

[0334] The hydrogen deposition and de-Al reaction was completed within 15 seconds, and after 2 minutes, a thin film powder intermediate product consisting mainly of nanosodium titanate thin films was recovered. This thin film powder intermediate product mainly had a thickness of less than 3 nm and an average area of ​​1000 nm. 2 The above two-dimensional sodium titanate thin film is composed of the above, and its TEM morphology is shown in Figure 1.

[0335] The above sodium nanotitanate thin film powder intermediate product was recovered without washing in order to retain residual base.

[0336] Under atmospheric pressure, the sodium titanate thin film powder intermediate was added to 50 ml of boiling water. While stirring, 3.5 g of Ba(OH)2·8H2O was dissolved in 10 ml of boiling water and added to the reaction system. During the reaction, the sodium titanate intermediate was replaced by barium titanate, and simultaneously, the sodium titanate thin film underwent a spherical transformation. Four minutes after the start of the reaction, the solid product in the reaction system was collected, yielding nanobarium titanate powder with a particle size range of 5 nm to 150 nm, mainly consisting of spherical or nearly spherical barium titanate particles. Figure 2 shows its morphology under low and high magnification SEM.

[0337] The obtained barium nanotitanate powder was heat-treated at 950°C for 1 hour in its free state, and then sintered and film-formed as shown in Figure 3. This indicates that the obtained barium nanotitanate powder has excellent low-temperature sinterability, suggesting potential applications in electronic ceramics fields such as multilayer chip ceramic capacitors.

[0338] [Example 2] Following the procedure of Example 1, a thin-film powder intermediate product mainly composed of a sodium nanotitanate thin film was first obtained and recovered.

[0339] After recovering the above-mentioned sodium nanotitanate film powder intermediate product, sand milling was performed without washing to remove residual base. Due to the large surface area of ​​the thin film, the dispersibility was improved while using fragments of the sodium titanate thin film (e.g., average area 500 nm). 2 It could be easily crushed into the following fragments.

[0340] The nano-sodium titanate thin film powder intermediate product, which had undergone the above sand milling, grinding, and dispersion processes, was added to 100 ml of boiling water. While stirring, 3.5 g of Ba(OH)2·8H2O was dissolved in 10 ml of boiling water and added to the reaction system. During the reaction, the sodium titanate thin film intermediate product was replaced by barium titanate, and at the same time, the sodium titanate thin film underwent a spherical transformation. Five minutes after the start of the reaction, the solid product in the reaction system was collected to obtain nano-barium titanate powder mainly consisting of spherical or nearly spherical barium titanate particles. Because the intermediate product was finely milled, the particle size range of the obtained product was 5 nm to 45 nm.

[0341] The spherical or nearly spherical barium nanotitanate powder having the above-mentioned aggregation characteristics was further subjected to sand milling and dispersion treatment to obtain spherical or nearly spherical ultrafine barium nanotitanate powder with excellent dispersibility, with a powder particle size range of 5 nm to 40 nm.

[0342] [Example 3] Ti 25 Al 75 According to the nominal composition (atomic percentage), the Ti and Al raw materials are melted and Ti 25 Al 75 A molten alloy mainly composed of was obtained. The obtained molten alloy was fabricated into an initial alloy mainly composed of TiAl3 intermetallic compounds in ribbon-like form with a thickness of ~20 μm by copper roller strip casting.

[0343] A 110 ml solution of 10 mol / L NaOH was prepared, and 3.5 g of Ba(OH)2·8H2O was dissolved in this NaOH solution. After heating the base solution to its boiling point under normal pressure, Ti 25 Al 75 0.8g of initial alloy ribbon was added to a base solution and reacted.

[0344] The hydrogen deposition and de-algae reaction was completed within 30 seconds. During the reaction, the initial alloy ribbon first underwent hydrogen deposition and de-algae to transform into a sodium titanate thin film intermediate, which was then immediately replaced by barium titanate. Simultaneously, the sodium titanate thin film intermediate transformed into a spherical shape.

[0345] 3.5 min after the start of the hydrogen deposition and de-Al reaction, the solid product in the reaction system was collected to obtain nanobarium titanate powder mainly consisting of spherical or nearly spherical barium titanate particles. Its SEM morphology is shown in Figure 4. As can be seen from the figure, its morphology consists mainly of two types. One is aggregates of fine particles, with individual fine nanoporous "band" units (non-free "spheroidized" units) having a particle size range of 5 nm to 60 nm. These small units aggregate to form aggregates with a particle size of approximately 1 μm, and these aggregated powder particles may be related to entangled aggregated sodium titanate thin film intermediate products. The other is incomplete hollow spherical shell particles with an outer diameter of 10 nm to 120 nm and a shell thickness of less than 10 nm, and each of these hollow spherical shell particles may have evolved from the reaction of a certain sodium titanate thin film intermediate product. When the obtained barium nanotitanate powder was heat-treated at 850°C for 4 hours in a compression-molded state, the powder sintered and formed a film. This indicates that the obtained barium nanotitanate powder has excellent low-temperature sinterability and shows promising potential for application in the field of electronic ceramics, such as multilayer chip ceramic capacitors.

[0346] [Example 4] Ag1Ti 24.75 Al 74.25 According to the nominal composition (atomic percentage), Ag, Ti, and Al raw materials are melted to form Ag1Ti 24.75 Al 74.25 A molten alloy mainly composed of was obtained. The obtained molten alloy was used to produce an initial alloy mainly composed of a TiAl3(Ag) intermetallic compound in which Ag elements were dissolved in ribbon-like structures with a thickness of ~20 μm, by the copper roller strip casting method.

[0347] Under normal pressure, the Ag1Ti manufactured as described above 24.75 Al 74.250.25 g of initial alloy ribbon is added while stirring to 50 ml of 10 mol / L NaOH aqueous solution at its boiling point (approximately 119°C), and Ag1Ti 24.75 Al 74.25 The initial alloy ribbon was nanofragmented by vigorous hydrogen deposition and de-Al reactions during reaction with a concentrated base solution, while its shape and composition were simultaneously reconfigured, producing a nano-sodium titanate thin film powder intermediate product in which Ag element was intrinsically doped in-situ in the form of atoms or atomic clusters.

[0348] The hydrogen deposition and de-Al reaction was completed within 15 seconds. After maintaining the temperature for 3 minutes to confirm that the reaction was completely finished, 1 g of Ba(OH)2·8H2O was dissolved in 5 ml of boiling water and added to the reaction system while stirring. During the reaction, the sodium titanate thin film intermediate product, which was intrinsically doped with Ag in situ, was replaced with intrinsically doped nanobarium titanate, and a spherical mutation occurred in the sodium titanate thin film matrix. After 3 minutes of mixing, the solid product in the reaction system was collected, yielding a powder mainly consisting of spherical or nearly spherical intrinsically doped nanobarium titanate particles with a particle size range of 5 nm to 150 nm. An SEM image of this powder is shown in Figure 5.

[0349] The barium nanotitanate powder, in which the above-mentioned Ag element having a certain aggregation characteristic was intrinsically doped in situ, was subjected to sand mill dispersion treatment to obtain barium nanotitanate powder intrinsically doped in situ with excellent dispersibility, and the powder particle size range was 5 nm to 140 nm.

[0350] [Example 5] Nd 0.2 Ti 24.8 Al 75 According to the nominal composition (atomic percentage), the rare earth element Nd is dissolved in Ti. 99.5 Nd 0.5 , Ag, Ti and Al raw materials are melted and Nd 0.2 Ti 24.8 Al 75A molten alloy mainly composed of was obtained. The obtained molten alloy was used to produce an initial alloy mainly composed of a TiAl3(Nd) intermetallic compound in which ribbon-like Nd elements were dissolved, with a thickness of approximately 20 μm, by the copper roller strip casting method.

[0351] Under normal pressure, the above-manufactured Nd 0.2 Ti 24.8 Al 75 Add 0.25 g of initial alloy ribbon to 50 ml of 10 mol / L NaOH aqueous solution with a boiling point (approximately 119°C) while stirring, and then add Nd 0.2 Ti 24.8 Al 75 The initial alloy ribbon was nanofragmented by vigorous hydrogen deposition and de-Al reactions during reaction with a concentrated base solution, while its shape and composition were simultaneously reconfigured, producing a nano-sodium titanate thin film powder intermediate product in which Nd element was intrinsically doped in-situ in the form of atoms or atomic clusters.

[0352] The hydrogen deposition and de-Al reaction was completed within 15 seconds. After maintaining the temperature for 3 minutes to confirm that the reaction was completely finished, 1 g of Ba(OH)2·8H2O was dissolved in 5 ml of boiling water and added to the reaction system while stirring. During the reaction, the sodium titanate thin film intermediate product, which was intrinsically doped with Nd in situ, was replaced with intrinsically doped nanobarium titanate nanoparticles, and a spherical mutation occurred in the sodium titanate thin film matrix. After 3 minutes of mixing, the solid product in the reaction system was collected, yielding a powder consisting mainly of spherical or nearly spherical intrinsically doped nanobarium titanate particles with a particle size range of 5 nm to 75 nm. An SEM image of this powder is shown in Figure 6.

[0353] The barium nanotitanate powder, in which Nd elements possessing the aforementioned specific aggregation characteristics were intrinsically doped in situ, was subjected to sand mill dispersion treatment to obtain barium nanotitanate powder intrinsically doped with Nd elements having excellent dispersibility, with a powder particle size range of 5 nm to 60 nm.

[0354] [Example 6] Zr3 Ti 22 Al 75 According to the nominal composition (atomic percentage), Zr, Ti, and Al raw materials are melted to form Zr3Ti 22 Al 75 A molten alloy mainly composed of was obtained. The obtained molten alloy was used to produce an initial alloy mainly composed of TiAl3(Zr) intermetallic compounds in which ribbon-like Zr elements were dissolved, with a thickness of 20 μm to 30 μm, by the copper roller strip casting method.

[0355] Under normal pressure, the Zr3Ti manufactured as described above 22 Al 75 0.25 g of initial alloy ribbon is added while stirring to 50 ml of 10 mol / L KOH aqueous solution at its boiling point (approximately 125°C), and Zr3Ti 22 Al 75 The initial alloy ribbon was nanofragmented by a vigorous hydrogen deposition and de-Al reaction during reaction with a concentrated base solution, while its shape and composition were simultaneously reconfigured, producing a nano-potassium titanate thin film powder intermediate product in which Zr element was intrinsically doped in-situ in the form of atoms or atomic clusters.

[0356] The hydrogen deposition and de-Al reaction was completed within 15 seconds. After maintaining the temperature for 3 minutes to confirm that the reaction was completely finished, 0.20 g of LiCl was added to the reaction system while stirring. During the reaction, the potassium titanate thin film intermediate product, which was intrinsically doped with Zr in situ, was replaced by lithium nanotitanate which was also intrinsically doped with Zr in situ, and at the same time, spherical deformation occurred in the potassium titanate thin film matrix. After 3 minutes of mixing, the solid product in the reaction system was collected, yielding a powder consisting mainly of spherical or nearly spherical lithium nanotitanate particles intrinsically doped with Zr in situ, with a particle size range of 5 nm to 150 nm.

[0357] [Example 7] Au1Ti 23 Al 75 According to the nominal composition (atomic percentage), Au, Ti, and Al raw materials are melted and Au1Ti 23 Al75 A molten alloy mainly composed of was obtained. The obtained molten alloy was then processed by copper roller strip casting to produce an initial alloy mainly composed of a TiAl3(Au) intermetallic compound in which ribbon-shaped Au elements were dissolved, with a thickness of 20 μm to 30 μm.

[0358] Under normal pressure, the Au1Ti manufactured as described above 23 Al 75 0.25 g of initial alloy ribbon is added while stirring to 50 ml of 10 mol / L NaOH aqueous solution at its boiling point (approximately 119°C), and Au1Ti 23 Al 75 The initial alloy ribbon was nanofragmented by vigorous hydrogen deposition and de-Al reaction during reaction with a concentrated base solution, while its shape and composition were simultaneously reconfigured, producing a sodium nanotitanate thin film powder intermediate product in which the element Au was intrinsically doped in-situ in the form of Au nanoparticles. Here, the particle size of the Au nanoparticles ranged from 2 nm to 10 nm.

[0359] The hydrogen deposition and de-Al reaction was completed within 15 seconds. After maintaining the temperature for 3 minutes to confirm that the reaction was completely finished, 1 g of Ba(OH)2·8H2O was added to the reaction system while stirring. During the reaction, the sodium titanate thin film intermediate product, which was intrinsically doped with Au in situ, was replaced by intrinsically doped lithium nanotitanate, and a spherical mutation occurred in the sodium titanate thin film matrix. After 3 minutes of mixing, the solid product in the reaction system was collected, yielding a powder mainly consisting of spherical or nearly spherical intrinsically doped lithium nanotitanate particles. The particle size range was 5 nm to 150 nm, and the particle size of the doped Au nanoparticles was 2 nm to 10 nm.

[0360] [Example 8] Ti 25 Al 75 According to the nominal composition (atomic percentage), the Ti and Al raw materials are melted and Ti 25 Al 75A molten alloy mainly composed of was obtained. The obtained molten alloy was fabricated into an initial alloy mainly composed of TiAl3 intermetallic compounds in ribbon-like form with a thickness of ~30 μm by copper roller strip casting.

[0361] Under normal pressure, the above-manufactured Ti 25 Al 75 0.25 g of initial alloy ribbon was reacted with 20 ml of 10 mol / L NaOH aqueous solution at 35°C for 2 hours to obtain an initial pulverized nanoporous sodium titanate irregular coarse powder with a particle size of 0.1 μm to 5 μm and an internal porous band size of less than 5 nm, as shown in Figure 7.

[0362] The above nanoporous sodium titanate irregular crude powder intermediate product was recovered without washing in order to retain residual NaOH.

[0363] Under normal pressure, 2 g of Ba(OH)2·8H2O was added to 10 ml of water, and the solution was heated to its boiling point. Then, the above-mentioned nanoporous sodium titanate irregular coarse powder was added to the solution under ultrasonic stirring and reacted for 10 minutes. After that, the solid powder was collected to obtain nanobarium titanate powder consisting mainly of spherical or nearly spherical barium titanate particles, with a powder particle size range of 5 nm to 150 nm.

[0364] [Example 9] Ti 25 Al 75 According to the nominal composition (atomic percentage), the Ti and Al raw materials are melted and Ti 25 Al 75 A molten alloy mainly composed of was obtained. The obtained molten alloy was fabricated into an initial alloy mainly composed of TiAl3 intermetallic compounds in ribbon-like shapes with a thickness of ~25 μm by the copper roller strip casting method.

[0365] Under normal temperature and pressure, 0.5 g of the initial alloy ribbon prepared as described above was sealed in a PTFE-lined reaction vessel along with 50 ml of a 10 mol / L NaOH aqueous solution. The temperature of the sealed reaction vessel, the initial alloy, and the NaOH aqueous solution inside was immediately raised to 250°C within 10 minutes, and then maintained at that temperature for 20 minutes. At this time, the pressure inside the reaction vessel was higher than atmospheric pressure.

[0366] After 20 minutes, the reaction vessel was rapidly cooled by placing it in cold water. After the reaction vessel cooled to room temperature, the pressure inside the vessel was returned to atmospheric pressure, and the solid matter inside the reaction vessel was separated from the solution to obtain an intermediate product of sodium titanate nanotube powder with an outer diameter of 3 nm to 12 nm.

[0367] The sodium titanate nanotube powder intermediate product described above was recovered without washing in order to retain residual NaOH.

[0368] Under atmospheric pressure, 4 g of Ba(OH)2·8H2O was added to 20 ml of water, and the solution was heated to its boiling point. Then, the sodium titanate nanotube powder intermediate product was added to the solution under ultrasonic stirring and reacted for 10 minutes. After that, the solid powder was collected to obtain nanobarium titanate powder consisting mainly of spherical or nearly spherical barium titanate particles, with a powder particle size range of 5 nm to 200 nm.

[0369] [Example 10] Ti 40 Al 60 According to the nominal composition (atomic percentage), the Ti and Al raw materials are melted and Ti 40 Al 60 A molten alloy mainly composed of was obtained. The obtained molten alloy was fabricated into an initial alloy consisting mainly of TiAl2 intermetallic compounds and TiAl intermetallic compounds in ribbon-like shapes with a thickness of ~1 mm by the copper roller strip casting method.

[0370] Under normal pressure, the above-manufactured Ti 40 Al 60 Add 0.25g of initial alloy ribbon to 50ml of 10mol / L KOH aqueous solution at its boiling point (approximately 150°C) while stirring, and then add Ti 40 Al 60The initial alloy ribbon is nanofragmented by vigorous hydrogen deposition and de-algae reactions during reaction with a concentrated base solution, simultaneously reconstructing its shape and composition to obtain a nanopotassium titanate thin film powder material. The thickness of a single film is approximately 0.25 nm to 3 nm, and the average area of ​​a single film is 1000 nm. 2 That was all.

[0371] The potassium nanotitanate thin film powder material separated from the above base solution is dispersed in water, and a 0.025 mol / L HCl solution is gradually added while stirring to continuously lower the pH of the mixed solution until the pH is controlled to 2-5. After 10 minutes, the mixture is separated, washed, and dried to obtain a nanotitanate thin film. The thickness of a single film is approximately 0.25 nm to 3 nm, and the average area of ​​a single film is 1000 nm. 2 That was all.

[0372] Under atmospheric pressure, the above titanic acid thin film powder intermediate product was added to 20 ml of boiling water, and while stirring, Ba(OH)2·8H2O was dissolved in 5 ml of boiling water and added to the reaction system. During the reaction, the titanic acid thin film intermediate product was replaced by barium titanate, and at the same time, the titanic acid thin film gradually became spherical.

[0373] In route 1, the volume of the solution was maintained by replenishing water, and after reacting for 20 minutes, the solid material was collected and heated to 300°C and kept warm for 5 minutes to further accelerate the spheroidization process, yielding nanobarium titanate powder consisting mainly of spherical or nearly spherical barium titanate particles with a particle size range of 10 nm to 150 nm. Its SEM morphology is shown in Figure 8.

[0374] In route 2, the volume of the solution was maintained by replenishing water, and after reacting for 8 minutes, the solid material was collected and heated to 900°C and held for 1 minute to further promote the spheroidization process, yielding nanobarium titanate powder consisting mainly of spherical or nearly spherical barium titanate particles with a particle size range of 10 nm to 300 nm. Its SEM morphology is shown in Figure 9. The above nanobarium titanate powder with certain aggregation characteristics was subjected to sand mill dispersion treatment to obtain spherical or nearly spherical nanobarium titanate powder with excellent dispersibility, and its particle size range was 10 nm to 300 nm.

[0375] [Example 11] Ti 25 Al 75 According to the nominal composition (atomic percentage), the Ti and Al raw materials are melted and Ti 25 Al 75 A molten alloy mainly composed of was obtained. The obtained molten alloy was fabricated into an initial alloy mainly composed of TiAl3 intermetallic compounds in ribbon-like form with a thickness of ~20 μm by copper roller strip casting.

[0376] Under normal pressure, the above-manufactured Ti 25 Al 75 Add 0.8g of initial alloy ribbon to 110ml of NaOH aqueous solution with a concentration of 10 mol / L and boiling point (approximately 119°C) while stirring, and Ti 25 Al 75 During the reaction with a concentrated base solution, the initial alloy ribbon was nanofragmented by a vigorous hydrogen deposition and de-algae reaction, while its shape and composition were simultaneously reconfigured, producing a nano-sodium titanate thin film powder intermediate product.

[0377] The hydrogen deposition and de-Al reaction was completed within 15 seconds, and after 2 minutes, mainly less than 3 nm thick with an average area of ​​1000 nm. 2 The thin-film powder intermediate product, mainly consisting of nano-sodium titanate thin films composed of the two-dimensional sodium titanate thin films described above, was recovered.

[0378] The above sodium nanotitanate thin film powder intermediate product is ground in a sand mill and mixed with BaCO3 powder, where Ba2+ The ratio of the molar content of to the molar content of Ti in the nanotitanium sodium thin film powder intermediate product was in the range of approximately 1:1. The mixed powder was compressed and molded, then subjected to a solid-phase reaction at 1000°C for 1 hour, followed by grinding and dispersion by ball milling and sand milling to obtain a nanotitanium barium particle powder product, with a powder particle size range of 20 nm to 300 nm.

[0379] [Example 12] Ti 25 Zn 75 According to the nominal composition (atomic percentage), the Ti and Zn raw materials are melted and Ti 25 Zn 75 A molten alloy mainly composed of was obtained. The obtained molten alloy was fabricated into an initial alloy mainly composed of TiZn3 intermetallic compounds in ribbon-like shapes with a thickness of ~30 μm by the copper roller strip casting method.

[0380] Under normal pressure, the above-manufactured Ti 25 Zn 75 Add 0.25g of initial alloy ribbon to 50ml of 15mol / L KOH aqueous solution at a temperature of 105°C to 115°C while stirring, and then add Ti 25 Zn 75 The initial alloy ribbon is nanofragmented by vigorous hydrogen deposition and de-Zn reactions during reaction with a concentrated base solution, simultaneously reconstructing its shape and composition to obtain a nanopotassium titanate thin film powder material. The thickness of a single film is approximately 0.25 nm to 3 nm, and the average area of ​​a single film is 1000 nm. 2 That was all.

[0381] The hydrogen deposition and de-Zn reaction was completed within 30 seconds. After maintaining the temperature for 3 minutes and stirring, 1 g of Ba(OH)2·8H2O was dissolved in 5 ml of boiling water and added to the reaction system. During the reaction, the potassium nanotitanate intermediate product was replaced by barium titanate, and at the same time, spherical deformation occurred in the potassium titanate thin film matrix. After 40 seconds of the mixing reaction, the solid product in the reaction system was collected, yielding a barium nanotitanate powder consisting mainly of spherical or nearly spherical barium titanate particles, with a particle size range of 5 nm to 80 nm.

[0382] The spherical or nearly spherical barium nanotitanate powder having the above-mentioned specific aggregation characteristics was subjected to sand mill dispersion treatment to obtain spherical or nearly spherical barium nanotitanate powder with excellent dispersibility, and the powder particle size range was 5 nm to 75 nm.

[0383] The technical features of the embodiments described above may be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the embodiments described above have been described, but any combination of these technical features should be considered to fall within the scope described herein, as long as it is inconsistent.

[0384] The embodiments described above merely illustrate some of the embodiments of the present invention, and although the description is relatively specific and detailed, it should not be understood as limiting the scope of protection of the invention. Furthermore, those skilled in the art can make several modifications and improvements as long as they do not depart from the concept of the present invention, and all of these fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be in accordance with the attached claims.

Claims

1. A method for producing doped barium nanotitanium / lithium powder, An initial alloy is manufactured, the initial alloy containing element T, Ti, and E, and the phase composition of the initial alloy includes a T-Ti(E) intermetallic compound in which element E is in solid solution, or a T-Ti-E intermetallic compound containing element E, where the molar ratio of element E to element Ti in the T-Ti(E) intermetallic compound or T-Ti-E intermetallic compound is 0 ≤ C Ｅ / C Ｔｉ Step 1 comprises ≤0.30, where element T includes at least one of Al and Zn, and element E includes at least one of Zr, Hf, Cr, V, Nb, Ta, W, Mo, Mn, Fe, Ni, Co, Sn, Pb, Bi, B, Be, Au, Pt, Pd, Ru, Rh, Re, Os, Ir, Ag, Cu, and RE, where RE is at least one rare earth element. The initial alloy is subjected to a hydrogen deposition and de-T reaction with a base solution mainly consisting of NaOH / KOH to obtain an intermediate powder product whose composition mainly includes at least one of the following: a nanosodium / potassium titanate thin film powder in which element E is in-situ endogenously doped; a nanoporous sodium / potassium titanate irregular powder in which element E is in-situ endogenously doped; and a nanosodium / potassium titanate tube (rod) in which element E is in-situ endogenously doped, or the element E is in-situ endogenously doped Step 2 involves reacting an intermediate powder product consisting of intrinsically doped sodium / potassium nanotitanate with a dilute acid to obtain an intermediate powder product of nanotitanate intrinsically doped with element E substituted with hydrogen ions, the composition of which mainly comprises at least one of a nanotitanate thin film powder intrinsically doped with element E, a nanoporous titanate disordered powder intrinsically doped with element E, and a nanotitanate tube (rod) intrinsically doped with element E. The intermediate powder product is subjected to a predetermined temperature, pressure, and medium atmosphere, Ba ２＋ / Li ＋ Step 3 involves reacting the contained barium / lithium source material with the non-spherical intermediate powder product for a certain period of time to cause a cation substitution reaction and a "sphericalization" morphological change in the non-spherical intermediate powder product, thereby obtaining a nanobarium / lithium titanate particle powder product in which spherical or substantially spherical E elements are intrinsically doped in situ. A method for producing doped barium nanotitanium / lithium powder, characterized by containing the following:

2. A method for producing doped barium / lithium nanotitanate powder according to claim 1, wherein the initial alloy is reacted with a base solution having NaOH / KOH as the main composition to obtain different intermediate powder products under different reaction conditions, 1) Under normal pressure, when the NaOH / KOH concentration is high and the temperature of the base solution is high, the intermediate powder product mainly contains sodium / potassium nanotitanate thin film powder in which element E is intrinsically doped in situ. 2) Under normal pressure, when the NaOH / KOH concentration is low and the temperature of the base solution is low, the intermediate powder product mainly consists of nanoporous sodium / potassium titanate disordered powder in which element E is intrinsically doped in situ. 3) Under normal pressure, with a moderate NaOH / KOH concentration and a moderate temperature of the base solution, the intermediate powder product mainly consists of a nanoporous sodium / potassium titanate irregular powder in which element E is intrinsically doped in situ, and a nanosodium / potassium titanate thin film powder in which element E is intrinsically doped in situ. 4) The reaction takes place in a sealed container under pressure higher than atmospheric pressure, with a high NaOH / KOH concentration and a temperature of the boiling point T at 1 atmosphere. ｆ溶液 A method for producing doped barium / lithium nanotitanate powder, characterized in that, when the temperature is higher than the intermediate powder product mainly contains nanotitanate tubes (rods) in which element E is intrinsically doped in situ.

3. A method for producing doped barium / lithium nanotitanate powder according to claim 1, wherein the basic method for in-situ intrinsically doping of element E comprises at least one of the following two methods a) and b): a) Element E is intrinsically embedded in the sodium / potassium titanate or titanate intermediate powder product in the form of E nanoparticles or E oxide nanoparticles, where the E nanoparticles or E oxide nanoparticles are in a different phase from the sodium / potassium titanate or titanate matrix. b) A method for producing doped barium / lithium nanotitanium powder, characterized in that element E is intrinsically embedded in a sodium / potassium titanate or titanate intermediate powder product in the form of E atoms or atomic clusters, wherein the E atoms or atomic clusters do not form a different phase with respect to the sodium / potassium titanate or titanate matrix, or do not form a distinctly different phase.

4. A method for producing doped barium titanate / lithium powder according to claim 1, wherein the conditions for "spheroidization" and cation substitution reaction in the non-spherical intermediate powder product are that the medium atmosphere is mainly a solution medium, the pressure is normal pressure or above normal pressure, and the barium / lithium source substance is mainly Ba ２＋ / Li ＋ in the form of a water-soluble salt or base containing, and the reaction temperature is 30°C - T ｆ溶液媒体 where T ｆ溶液媒体 is the boiling point temperature of the solution medium at normal pressure. A method for producing doped barium titanate / lithium powder, characterized by the above.

5. A method for producing doped barium / lithium nanotitanate powder according to claim 1, characterized in that the average particle size range of the barium / lithium nanotitanate particles, in which the element E is intrinsically doped in situ, is 5 nm to 300 nm.

6. A method for producing doped barium nanotitanium / lithium powder according to claim 1, wherein the Ba ２＋ / Li ＋ Barium / lithium source materials containing Ba ２＋ / Li ＋ Bases and Ba ２＋ / Li ＋ A method for producing doped barium / lithium nanotitanium powder, characterized by containing at least one salt containing [the specified substance].

7. A method for producing doped barium / lithium nanotitanate powder according to claim 1, wherein the medium atmosphere is non-solution, step 3 specifically involves the intermediate powder product of step 2 being Ba ２ + / Li ＋ A barium / lithium source material containing the barium is mixed with ball mill grinding and sand mill grinding, and a solid-phase reaction is carried out, in which the Ba in the reaction system ２＋ / Li ＋ A method for producing doped barium nanotitanate / lithium powder, characterized in that the ratio of the molar content of to the molar content of Ti in the intermediate powder product is in the range of 0.75:1 to 1.25:1, and after the reaction is completed, the product is ground and dispersed by ball milling or sand milling to obtain a barium nanotitanate / lithium particle powder product in which element E is intrinsically doped in situ.

8. A method for producing doped barium / lithium nanotitanate powder according to claim 1, wherein if the primary "spheroidization" in step 3 is insufficient, (1) A method for further shrinking the non-free "spheroidized" units by placing the reaction system in a sealed container and treating it at high temperature and high pressure for a certain period of time, thereby producing spherical or nearly spherical barium titanate / lithium nanoparticles with higher solidity and intrinsically doped with element E in situ, (2) A method in which the solution in the reaction system is continuously evaporated to dryness, the residual solid is heated to 150°C to 400°C without changing the reaction vessel, and the temperature is maintained for a certain period of time, A method for producing doped barium nanotitanium / lithium powder, characterized by improving the degree of "spheroidization" by at least one of the following three methods: (3) recovering the solids in the reaction system, heating them to 150°C to 1300°C, and maintaining the temperature for a certain period of time.

9. A method for producing doped barium nanotitanium / lithium powder according to claim 1, The element E mainly consists of at least one of Au, Pt, Pd, Ru, Rh, Re, Os, and Ir, and 0 < C Ｅ / C Ｔｉ If ≤0.01, element E is intrinsically doped in situ into the barium titanate / lithium powder product, mainly in the form of E atoms or atomic clusters. The element E mainly consists of at least one of Cu, Fe, Ni, and Co, and 0 < C Ｅ / C Ｔｉ If ≤ 0.02, element E is intrinsically doped in the barium titanate / lithium powder product mainly in the form of E atoms or atomic clusters. Element E mainly contains Ag, and 0 < C Ｅ / C Ｔｉ If ≤ 0.10, element E is intrinsically doped in the barium titanate / lithium powder product mainly in the form of E atoms or atomic clusters. Element E mainly consists of at least one of Zr and Hf, and 0 < C Ｅ / C Ｔｉ If ≤ 0.30, element E is intrinsically doped in the barium titanate / lithium powder product mainly in the form of E atoms or atomic clusters. Element E mainly consists of at least one of Cr, V, Nb, Ta, W, and Mo, and 0 < C Ｅ / C Ｔｉ If ≤ 0.10, element E is intrinsically doped in the barium titanate / lithium powder product mainly in the form of E atoms or atomic clusters. Element E mainly comprises at least one of Mn, Sn, Pb, Bi, B, Be, and RE, and 0 < C Ｅ / C Ｔｉ A method for producing doped nanobarium titanate / lithium powder, characterized in that, when ≤0.06, element E is intrinsically doped in the barium titanate / lithium powder product mainly in the form of E atoms or atomic clusters.

10. A method for producing doped barium / lithium nanotitanate powder according to claim 1, characterized in that steps 2 and 3 are combined to achieve the production of a barium / lithium nanotitanate particle powder product in which element E is intrinsically doped in situ by a one-pot method.

11. A method for producing doped barium / lithium nanotitanium powder according to claim 10, wherein the one-pot method combining steps 2 and 3 is: After the completion of step 2, Ba ２＋ / Li ＋ Barium / lithium source material containing Ba ２＋ / Li ＋ Method 1 involves adding a barium / lithium source solution containing the barium / lithium source solution to the reaction system in step 2 and continuing the reaction at a constant temperature for a certain period of time. At the start of step 2, Ba ２＋ / Li ＋ A method for producing doped barium / lithium nanotitanate powder, comprising two methods: 1) adding an appropriate amount of a barium / lithium source material containing to a reaction solution system together with NaOH / KOH, and reacting at a constant temperature for a certain period of time; and 2) reacting at a constant temperature for a certain period of time.

12. A method for producing doped barium / lithium nanotitanate powder according to claim 1, wherein the production method reduces the particle size of the barium / lithium nanotitanate particle powder product in which element E is intrinsically doped in situ, and the production method is Method 1 involves simultaneously applying ultrasonic treatment to the reaction system during the reaction process of step 2, or / and step 3. After step 3, mechanical grinding and dispersion processing is performed, and the mechanical grinding and dispersion processing method is method 2 which includes at least one of ball milling and sand milling, A method for producing doped barium / lithium nanotitanate powder, characterized in that, after step 2, the intermediate powder product is mechanically pulverized and dispersed, and the mechanical pulverization and dispersion process is carried out by at least one of three methods, including method 3, which includes at least one of ball milling and sand milling.

13. A method for producing doped barium / lithium nanotitanate powder according to claim 1, characterized in that the minimum sintering temperature of the spherical or substantially spherical barium / lithium nanotitanate particle powder product, in which the element E is intrinsically doped in situ, does not exceed 950°C.

14. Applications of an in-situ intrinsically doped barium / lithium nanotitanate powder material, produced by a method for producing doped barium / lithium nanotitanate powder according to any one of claims 1 to 13, in electronic ceramics, composite materials, paints, powder metallurgy, multilayer ceramic capacitors, thermistors, piezoelectric ceramics, and battery materials.

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