38 results about "Batio3 ceramics" patented technology

The invention provides a Joule heat ultrafast sintering preparation method of barium titanate ceramic with ultrahigh dielectric constant and low loss, which comprises the following steps: ball-milling and mixing barium titanate powder and copper oxide powder, drying, pressing into a cake-shaped sample, carrying out cold isostatic pressing to obtain a sample piece, and carrying out vacuum treatment on Joule heat ultrafast sintering equipment to obtain the barium titanate ceramic with ultrahigh dielectric constant and low loss. Putting the sample preparation sheet between two layers of graphite felts, and starting Joule heat ultrafast sintering equipment to enable the graphite felts to generate Joule heat, so as to realize short-time sintering of the barium titanate ceramic. According to the invention, a Joule heat ultrafast sintering technology is adopted, and Joule heat is generated by directly applying voltage and current to the graphite felt, so that the sintering time is greatly shortened, and environmental pollution is avoided; meanwhile, the dielectric constant of the barium titanate ceramic is greatly improved by adding copper oxide, and the energy consumption is remarkably reduced.

The present invention belongs to the technical field of the preparation of electronic ceramic components. More specifically, it relates to a preparation method of a high temperature coefficient thermosensitive material. Graphene is uniformly mixed with ceramic powder. After reduction sintering, graphene is uniformly dispersed at the grain boundaries of barium titanate ceramic grains. During the reoxidation process, graphene is oxidized and removed to form two-dimensional pores, which serve as oxygen transmission paths to promote the reoxidation of the ceramic grain boundaries to form barriers, thereby preparing a high-density, low reoxidation temperature, high temperature coefficient porous barium titanate-based thermosensitive ceramic. The present invention can be applied to the existing preparation process of barium titanate thermosensitive ceramics. By adding only a small amount of graphene, the reoxidation temperature of barium titanate thermosensitive ceramics can be reduced, and a barium titanate thermosensitive ceramic with high density, a relatively high rise-to-resistance ratio, and a high temperature coefficient can be prepared.

The present invention belongs to the field of absorbing materials, and in particular, relates to a fiber-reinforced barium titanate-polymer-converted ceramic-based composite absorbing material and a preparation method thereof. The composite absorbing material provided by the present invention includes a ceramic matrix and a fiber reinforcement embedded in the ceramic matrix; the ceramic matrix includes a barium titanate ceramic phase and a polymer-converted ceramic phase; the fiber reinforcement is composed of a plurality of layers of fiber cloth stacked together, and an interface layer is deposited on the surface of each layer of fiber cloth; the fibers in the plurality of layers of fiber cloth include a plurality of carbon fibers, silicon dioxide fibers, silicon carbide fibers, glass fibers, alumina fibers, and zirconium oxide fibers, and the interface layer is one or more of a PyC interface, a BN interface, and a SiC interface. The composite absorbing material provided by the present invention uses a plurality of fibers as reinforcements and a barium titanate-polymer-converted ceramic as a matrix, and has both excellent mechanical properties and absorbing properties.

This application relates to the field of electrochemical technology, specifically to polyester composite films and their preparation methods, composite current collectors and their preparation methods, electrodes and their applications. The polyester composite film of this application comprises: a polyester substrate layer and a first surface layer and a second surface layer respectively disposed on opposite sides of the polyester substrate layer; the polyester substrate layer comprises, by weight, 90 to 99 parts of polyester material and 1 to 10 parts of photo-straining material; the first and second surface layers comprise polyethylene terephthalate polymers; the transmittance of the first surface layer, the second surface layer, and the polyester material is independently 92% to 99%; the photo-straining material comprises one or more of barium titanate ceramics, lead zirconate titanate ceramics, PI / CNTs photosensitive composite materials, PEEK / anthraquinone photosensitive composite materials, MIL-101 chromium metal-organic frameworks, and UiO-66-NH2 / ZnO composite materials. The polyester composite film can easily break under high-destructive external forces such as battery breakdown and battery collision, effectively suppressing thermal runaway.

The invention relates to the technical field of barium titanate-based ceramic preparation, in particular to a rare earth ion doped barium titanate-based ceramic material and a preparation method thereof.High-purity tetragonal-phase barium titanate is prepared through a hydrothermal synthesis process, doped ions comprise two rare earth ion elements including europium and dysprosium, and one or more of sodium, magnesium, bismuth, niobium, cobalt, lanthanum and the like are cooperatively doped; barium titanate powder and ion-doped oxide powder are mixed according to a certain proportion, and the ion-doped barium titanate ceramic is prepared through solid-phase sintering. By adopting the formula and the preparation method disclosed by the invention, a barium titanate-based ceramic capacitor product with excellent dielectric property, high stability and low loss can be obtained, and the preparation method is suitable for preparing a high-temperature and high-performance multilayer ceramic capacitor.

This invention discloses a method for controlling the oxygen partial pressure and performance of barium titanate ceramics during sintering using coconut shells, comprising the following steps: Step 1: Select coconut shells, clean them, remove the fibers, and dehydrate and dry them using a high-temperature forced-air drying oven; Step 2: Crush the dried coconut shells into small pieces, place them in a crucible, and carbonize them at high temperature in a muffle furnace; Step 3: Take out the high-temperature carbonized coconut shell char, grind it, and sieve it; Step 4: Weigh the coconut shell char and barium titanate powder at a mass ratio of 2~6:100, and then grind them to fully mix the coconut shell char and barium titanate powder; Step 5: Add a binder to the mixed powder, grind it thoroughly, and then press the powder into sheets to obtain a green body of fully mixed coconut shell char and barium titanate; Step 6: Place the pressed green body into a muffle furnace and sinter it at high temperature; Step 7: Obtain the coconut shell char mixed barium titanate ceramic.

The application discloses a preparation method of a niobium-doped barium titanate ceramic material with improved flexoelectric performance, and relates to the field of functional materials. The preparation method comprises the following steps: (1) preparing a niobium-doped barium titanate powder by ball-milling and mixing high-purity barium titanate powder and niobium oxide powder and then solid-phase sintering; (2) preparing a to-be-used embryo by using the powder; (3) performing traditional sintering on the to-be-used embryo to obtain a niobium-doped barium titanate ceramic; and (4) performing flexoelectric performance testing on the niobium-doped barium titanate ceramic, wherein the flexoelectric coefficient of the niobium-doped barium titanate ceramic is 23-380 muC / m, and the flexoelectric coefficient of the component with the optimal flexoelectric performance is 20 times higher than that of a pure barium titanate ceramic.

The invention relates to the technical field of electrochemistry, in particular to a polyester composite film and a preparation method thereof, a composite current collector and a preparation method thereof, and an electrode and application thereof. The polyester composite film comprises a polyester substrate layer, a first surface layer and a second surface layer, wherein the first surface layer and the second surface layer are respectively arranged on two opposite sides of the polyester substrate layer; the polyester substrate layer comprises the following components in parts by weight: 90-99 parts of a polyester material and 1-10 parts of a photoinduced strain material; the components of the first surface layer and the second surface layer comprise a polyterephthalate polymer; the light transmittance of the first surface layer, the light transmittance of the second surface layer and the light transmittance of the polyester material are 92%-99% respectively and independently; the photoinduced strain material comprises one or more of barium titanate ceramic, lead zirconate titanate ceramic, a PI / CNTs photosensitive composite material, a PEEK / anthraquinone photosensitive composite material, an MIL-101 chromium metal organic framework and a UiO-66-NH2 / ZnO composite material. The polyester composite film can be easily broken under high-damage external force such as battery breakdown and battery collision, so that the thermal runaway phenomenon is effectively inhibited.

A method for improving the electrocaloric effect of ferroelectric perovskite material, by weighing Ba source, Sr source, Ca source, Hf source, Sn source, Zr source, Ti source and mixing uniformly according to stoichiometric ratio, pre-sintering to obtain (Ba x Sr y Ca z A 1‑x‑y‑z )(Hf a Sn b Zr c Ti d B 1‑a‑b‑c‑d )O3 powder; after fine grinding and mixing with binder, granulation, shaping, aging, plastic removal treatment to obtain ceramic green body; finally, through sintering, high electrocaloric performance barium titanate-based ferroelectric perovskite electrocaloric material is obtained, the application takes barium titanate ceramic as matrix, introduces zirconium, hafnium, tin, strontium, calcium and other element precursors during synthesis by solid phase method, simultaneously substitutes BaTiO3 material at A and B positions with multi-element doping, after blending, high temperature sintering to obtain finished product. The method has simple preparation condition, mature process, low cost and high reliability. Under the induction of electric field, great entropy change and electrocaloric effect are generated.

The invention relates to a wafer-type barium titanate ceramic capacitor dielectric material and a preparation method and application thereof, and the preparation method comprises the steps: uniformly mixing barium titanate-based mixed powder and stearate, pressing, and sintering to obtain the wafer-type barium titanate ceramic capacitor dielectric material, the raw materials of the barium titanate-based mixed powder comprise barium titanate, rare earth oxide and a silica sol solution. The stearate is used as an internal release agent to solve the problem of large release resistance in the subsequent pressing process due to the fact that silica sol liquid is used for replacing an organic binder to produce the wafer ceramic, and is also used as a doping source, and metal carbonate obtained in the subsequent heat treatment process is firstly filled in gaps of barium titanate particles to reduce the internal porosity of a green body; gaps of barium titanate particles are further filled with trace high-activity metal oxide obtained through further heat treatment, the surfaces of the barium titanate particles are wrapped with a vitreous liquid phase formed by silicon dioxide, then the dielectric constant is increased, the performance stability is improved, and the yield is remarkably increased.

The application discloses a kind of low dielectric ultra-low loss high temperature stability neodymium oxide and zinc niobate co-doped barium titanate ceramic and preparation method.The general formula of the ceramic material is (1-x) BaTiO3-xZnNb2O6-xNd2O3, wherein x is 0.1-0.2, and is prepared by traditional solid-phase sintering method, with simple process, good repeatability and high yield.The application introduces Zn 2+ , Nb 5+ And Nd 3+ A / B site collaborative doping is carried out in BaTiO3 matrix, so that the obtained ceramic material realizes excellent comprehensive performance in the range of x=0.145-0.155 while maintaining moderate dielectric constant: extremely low dielectric loss (tanδ≤0.001), excellent temperature stability (ΔC / C 20°C ≤±0.5%, -150-250°C) and high breakdown field strength (E b ≥280kV / cm).The ceramic material is suitable for scenes with strict requirements on dielectric properties, temperature stability and breakdown field strength, and can be applied in fields such as aerospace extreme environment electronic components, new energy vehicle power modules and precision high-frequency sensing equipment, with significant application value and market potential.

This invention discloses a low-dielectric-value, ultra-low-loss, high-temperature-stability barium titanate and zinc niobate co-doped barium titanate ceramic, and its preparation method. The ceramic material has the general formula 0.85BaTiO3-0.15ZnNb2O6-xDy2O3, where x ranges from 0.008 to 0.02. It is prepared using a traditional solid-state sintering method, which is simple, reproducible, and has a high yield. This invention introduces Zn into the BaTiO3 matrix. 2+ 、Nb 5+ and Dy 3+ Multi-doping was performed to achieve lattice manipulation and defect engineering in the BaTiO3 matrix. When x=0.15, the resulting ceramic material maintained a suitable dielectric constant. e r While achieving a dielectric loss of 138, it also achieves excellent overall performance: extremely low dielectric loss (tanδ=0.0002, 1kHz), and excellent temperature stability (Δδ). C / C 20°C With a voltage rating of ≤ ±0.5% (-150~200°C) and a high breakdown field strength of 330kV / cm, these performance indicators fully meet the highest standards of the new NPO type ceramic capacitors, and have significant application value and market prospects in high-end fields such as microwave communication, automotive electronics and aerospace.

The application provides a ceramic dielectric material and a preparation method and application thereof, a main body material of the material is BaTiO3, doping materials include SiO2, CaO, V2O5, ZrO2 and oxides of rare earth elements; the oxides of the rare earth elements include at least two of Sc2O3, Sm2O3, Dy2O3 and Ho2O3; the addition amount of BaTiO3 is 93.5-95 mol% in terms of molar percentage; the total addition amount of the doping materials is 4.6-7 mol%. The application takes BaTiO3 as the main body material, takes sintering aids, metal oxides and rare earth elements as composite dopants, modifies a barium titanate ceramic base, adds sintering aids and doping materials to refine particles, controls defects and improves the uniformity of the grain size, and prepares fine-grain ceramic and multilayer ceramic capacitors with high reliability, stable capacitance characteristics and more easy lamination.

The present invention discloses a secondary hydrothermal crystallization preparation method for a core-shell structured nano-modified barium titanate-based powder. The method uses a secondary hydrothermal reaction crystallization control technology to achieve nano-scaling and homogenization of the base material. A proton capture agent is added to reduce the proportion of mismatched OH-ions, minimizing the cubic metastable phase structure present at the phase transition point temperature. Bulk ion doping is used to suppress and broaden the Curie peak, thereby increasing the dielectric constant, reducing dielectric loss, and optimizing temperature characteristics. The method improves sintering characteristics and enhances dielectric properties by forming a core-shell structured nano-modified barium titanate-based powder. The method achieves the preparation of a core-shell structured nano-modified barium titanate-based powder, recycles excess barium chloride, sodium hydroxide, and hydrochloric acid, and is suitable for the efficient preparation of barium titanate ceramic powder for high-performance MLCCs.

The invention relates to a barium titanate high-voltage ceramic material as well as a solid-phase sintering preparation method and application thereof, and the solid-phase sintering preparation method comprises the following steps: mixing barium titanate powder and auxiliary material powder, and sintering the obtained mixed powder to obtain the barium titanate high-voltage ceramic material, the auxiliary material powder comprises strontium carbonate and titanium dioxide in a molar ratio of (0.8: 1)-(1.2: 1); the molar ratio of the barium titanate powder to the auxiliary material powder is (5: 1)-(10: 1). The dielectric property and the high-voltage resistance of the barium titanate ceramic in a high-voltage environment can be improved only by using simple auxiliary materials; in addition, the solid-phase sintering preparation method provided by the invention is simple and easy to implement, and can realize industrial large-scale production of the barium titanate high-voltage ceramic material.

The invention discloses light-cured piezoelectric ceramic slurry and a preparation method and application thereof.According to the light-cured piezoelectric ceramic slurry, two-functional-group aliphatic polyurethane acrylate, hexanediol diacrylate and trimethylolpropane triacrylate are compounded, a phosphate hyperdispersant is combined, firm chemical anchoring can be formed with modified barium titanate, and the piezoelectric ceramic slurry can be applied to light-cured piezoelectric ceramics. In addition, a curing system composed of low-viscosity active monomer hexanediol diacrylate, high-crosslinking-density trimethylolpropane triacrylate and a visible light initiator is adopted, the curing system is matched with the light absorption characteristic of modified barium titanate, and therefore the light absorption property of the modified barium titanate is improved. And enough penetration depth and interlayer binding force are ensured. A DLP technology is adopted to accurately print a ceramic green body framework at one time, a barium titanate ceramic framework with a complete structure and high density is obtained after degreasing and sintering, the 3-3 type piezoelectric composite material with controllable precision is prepared, the reflection loss of sound waves is reduced, and the quality of the material is further ensured.

The invention relates to a nanocrystalline barium titanate ceramic dielectric material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing barium titanate powder, a grain growth inhibitor and a binder, and carrying out normal pressure sintering to prepare the nanocrystalline barium titanate ceramic dielectric material, the grain growth inhibitor is composed of a combination of at least two of a magnesium source, an aluminum source or a silicon source. The nanocrystalline barium titanate ceramic dielectric material is prepared by taking at least two of a magnesium source, an aluminum source or a silicon source as grain growth inhibitors through a simple solid-phase coating method, the preparation method is simple, and the prepared nanocrystalline barium titanate ceramic dielectric material can be widely applied to the field of electronic ceramics and can be widely applied to the field of electronic ceramics. The method can be particularly used for multilayer ceramic capacitors.

This invention relates to electrode pastes, preparation methods, and components for PTC thermistors. It belongs to the field of electronic paste technology and aims to overcome the shortcomings of existing technologies. The paste provided by this invention is prepared from metal powder, glass powder, inorganic additives, organic additives, and resin. The metal powder includes copper-nickel alloy powder and pure copper powder. This technical solution effectively inhibits the diffusion of copper atoms into the barium titanate ceramic matrix, ensuring that the resistance value of the ceramic matrix after sintering differs from the original value by within ±2.0%, achieving stable and sufficient ohmic contact while avoiding the deterioration of the matrix's resistance. It also exhibits excellent solderability and high adhesion strength.

The invention belongs to the field of all-solid-state refrigeration materials, and particularly discloses a barium titanate-based ferroelectric ceramic electrocaloric material and a preparation method thereof. The chemical formula of the ceramic electrocaloric material is Ba1-x (Li0. 5Sm0. 5) xTi1-yZryO3, x is more than 0 and less than or equal to 0.2, and y is more than 0.01 and less than or equal to 0.1. According to the ceramic electrocaloric material, the electrocaloric performance and the temperature stability of the lead-free ferroelectric ceramic material are improved at the same time. The preparation process of the ceramic electrocaloric material is simple and high in repeatability, the lithium element, the samarium element and the zirconium element are subjected to solid solution in the lead-free barium titanate ceramic material at the same time, the solid solution elements enter Ba ion sites and Ti ion sites in crystal lattices of BaTiO3 respectively, the original crystal lattice structure is broken, the relaxation property of the barium titanate material is improved, and the performance of the ceramic electrocaloric material is improved. The material has the characteristics of high electrocaloric performance and wide working temperature area.

The application provides a barium titanate ceramic powder and a preparation method and application thereof, and belongs to the technical field of material preparation. The method comprises the following steps: mixing a barium chloride aqueous solution and a titanium chloride-containing solution, mixing the mixed solution with an organic acid solution, mixing the mixed sol solution with a surfactant solution, stirring and reacting, and sequentially performing centrifugation, drying, calcination and crushing on the stirring reaction product to obtain the barium titanate ceramic powder. Compared with the prior art, the application has the advantages that the simple co-precipitation preparation process is easy to operate and realize, the cost is low, no additional complex conditions and complex equipment are needed, the co-precipitation reaction can occur under stirring at normal temperature and pressure, the raw materials used are cheap and easy to obtain, the material preparation cost is relatively low, the particles are pure tetragonal phase crystal structures, the particle size is small, the prepared barium titanate is easy to process and sinter, and therefore the barium titanate can be used for manufacturing electronic ceramic devices, filter ceramic devices and various purposes.

The invention discloses a lead-free electrocaloric ceramic material and a preparation method thereof. Comprising the following steps that BaCO3, Sm2O3, Li2CO3 and TiO2 are weighed according to the stoichiometric ratio of Ba (1-2x) SmxLixTiO3, ceramic raw materials are subjected to ball milling, ceramic powder is obtained, and x is larger than 0.0 and smaller than or equal to 0.1; drying the ceramic powder, sintering for the first time, and then sequentially carrying out secondary ball-milling mixing, drying, sieving, granulating, dry pressing and cold isostatic pressing to prepare a ceramic green body; and sintering the ceramic green body for the second time, and then cooling along with the furnace to obtain the lead-free electrocaloric ceramic material. A defect dipole is formed by equivalently introducing trivalent samarium ions and monovalent lithium ions into a lead-free barium titanate ceramic material, and the defect dipole not only serves as an exogenous polarization factor to improve the polarizability of barium titanate, but also improves a breakdown electric field, so that the internal balance between the high breakdown electric field and high polarization is effectively relieved; therefore, the electrocaloric temperature change of the barium titanate ceramic is improved.

This invention relates to a fine-grained barium titanate ceramic dielectric material coated with bismuth borosilicate glass and its preparation method. A bismuth borosilicate glass sol is prepared using a sol-gel method, wherein the bismuth borosilicate glass is a Bi₂O₃-B₂O₃-SiO₂ glass. BaTiO₃ powder is dispersed in the bismuth borosilicate glass sol to obtain bismuth borosilicate glass sol-coated BaTiO₃ powder. The bismuth borosilicate glass-coated BaTiO₃ powder is calcined to obtain fine-grained barium titanate ceramic powder coated with bismuth borosilicate glass. The fine-grained barium titanate ceramic powder coated with bismuth borosilicate glass is granulated and shaped to obtain a barium titanate ceramic green body. Heating further yields a fine-grained barium titanate dielectric ceramic, which is the fine-grained barium titanate ceramic dielectric material coated with bismuth borosilicate glass. Compared with the prior art, the present invention prepares glass-coated BaTiO3 powder to form a core-shell structure powder by sol-gel method. This core-shell structure powder of glass-coated BaTiO3 powder is used for the preparation of fine-grained barium titanate ceramics and can be widely used in the field of electronic materials applications.

The invention discloses modified barium titanate ceramic particles with low Curie temperature point and low resistivity at room temperature as well as a preparation method and application of the modified barium titanate ceramic particles. The room-temperature resistivity of the modified barium titanate ceramic particles with the low Curie temperature point and the room-temperature low resistivity ranges from 0.6 ohm.cm to 4 ohm.cm, the Curie temperature point ranges from 45 DEG C to 55 DEG C, and the modified barium titanate ceramic particles are prepared from 2 mol to 3 mol of barium titanate hydrothermal powder, 0.2 mol to 0.8 mol of a Curie temperature point peak shifting agent, 0.001 mol to 0.01 mol of rare earth oxide, 0.1 mol to 0.4 mol of silicon dioxide powder, 0.2 mol to 0.5 mol of titanium dioxide powder and 0.2 mol to 0.5 mol of nickel metal powder. The modified barium titanate ceramic particles with low Curie temperature point and low resistivity at room temperature can be applied to waste lithium battery recovery, can realize rapid discharge and prevent thermal runaway, have enough mechanical strength, and can be reused.

The invention relates to a barium titanate high-frequency ceramic material as well as a solid-phase sintering preparation method and application thereof, and the solid-phase sintering preparation method comprises the following steps: mixing barium titanate powder and additive powder, and sintering the obtained mixed powder to obtain the barium titanate high-frequency ceramic material, the additive powder is prepared from the following raw materials: BaCO3, Li2CO3 and Nb2O5 according to a molar ratio of (7 to 9): 1: (2 to 4); the molar ratio of the barium titanate powder to the additive powder is (80: 1)-(99: 1). The dielectric property of the barium titanate ceramic in a high-frequency environment can be improved only by using simple auxiliary materials; moreover, the solid-phase sintering preparation method provided by the invention is simple and easy to implement, and can realize industrial large-scale production of the barium titanate high-frequency ceramic material.

The invention discloses a barium titanate ceramic capacitor material and a preparation method thereof, the composition of the barium titanate ceramic capacitor material is represented as (1-a-b-c-d-e) BaTiO3-aNb2O5-bGd2O3-cB2O3-dSiO2-eMn3O4, a = 0.008-0.012, b = 0.002-0.005, c = 0.001-0.004, d = 0.001-0.004, and e = 0.002-0.004, the preparation method comprises the following steps: (1) mixing Nb2O5, Gd2O3, B2O3, SiO2 and Mn3O4 according to a ratio, carrying out mixing, ball milling and sieving, and then carrying out first sintering treatment; (2) adding BaTiO3 into the material prepared in the step (1), mixing and ball-milling, and drying; and (3) carrying out compression molding on the material obtained in the step (2), and then carrying out secondary sintering treatment. The barium titanate ceramic capacitor material disclosed by the invention realizes low loss and high temperature stability while keeping relatively high dielectric.

The invention provides a preparation method of a one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material, and belongs to the technical field of dielectric materials. The preparation method comprises the following steps: uniformly mixing tetrabutyl titanate, zirconium acetylacetonate and an organic solvent to form a solution A, and uniformly mixing barium acetate, strontium acetate and deionized water to form a solution B; slowly adding the solution B into the solution A, carrying out a reaction step by step, and aging after the reaction is finished to obtain a wet gel-like ceramic precursor; thickening the ceramic precursor, and then performing electrostatic spinning to obtain a nanofiber membrane; calcining the nanofiber membrane, and then scattering the nanofiber membrane into nanorods; and mixing the nanorod and PVDF in an organic solvent, dispersing into a suspension, heating and stirring, and carrying out curtain coating and hot pressing to obtain the composite material. The composite material disclosed by the invention has relatively high comprehensive performance and has an important application prospect in the field of energy storage.

The invention discloses a BaTiO3-Nb2O5 (at) PDA (Personal Digital Assistant) nano particle as well as preparation and application thereof. The BaTiO3-Nb2O5 (at) PDA nano particle comprises a Nb2O5 doped BaTiO3 nano particle inner core and a PDA coating layer, wherein the nano particle inner core is coated with the PDA coating layer; the dielectric constant and the conductivity of BaTiO3 ceramic are remarkably improved through doping of Nb2O5, meanwhile, the loss is reduced, and through a PDA coating technology, the dispersity and the stress transmission efficiency between two phases of nanoparticles and a fluorine-containing polymer in the piezoelectric film are further improved, and cracks and defects are reduced, so that the overall piezoelectric property of the film is improved; according to the invention, BaTiO3-Nb2O5-coated PDA nanoparticles and MWCNTs are used as fillers, so that the beta-phase content and crystallinity of the film are synergistically improved, the dispersibility of a matrix phase and a filler phase is improved, and the piezoelectric property of the film is optimized.

This invention relates to a barium titanate high-pressure ceramic material, its solid-state sintering preparation method, and its application. The solid-state sintering preparation method includes: mixing barium titanate powder and auxiliary powder, and then sintering the resulting mixed powder to obtain the barium titanate high-pressure ceramic material. The auxiliary powder comprises strontium carbonate and titanium dioxide in a molar ratio of 0.8:1 to 1.2:1; the molar ratio of barium titanate powder to auxiliary powder is 5:1 to 10:1. This invention improves the dielectric properties and high-voltage resistance of barium titanate ceramics under high-voltage environments using only simple auxiliary materials. Moreover, the solid-state sintering preparation method provided by this invention is simple and easy to implement, enabling the industrial-scale production of barium titanate high-pressure ceramic materials.

A method for improving the electrocaloric effect of a ferroelectric perovskite material, comprising: weighing Ba, Sr, Ca, Hf, Sn, Zr, and Ti sources and mixing same uniformly according to a stoichiometric ratio; performing pre-sintering to obtain (BaxSryCazA1-x-y-z)(Hf aSn bZrcTidB1-a-b-c-d)O3 powder; after fine grinding and mixing with a binder, granulating the mixture, followed by forming, aging, and de-plasticizing to obtain a ceramic green body; and finally performing sintering to obtain a barium titanate-based ferroelectric perovskite electrocaloric material having high electrocaloric performance. In the present invention, barium titanate ceramic is used as a matrix, and elemental precursors such as zirconium, hafnium, tin, strontium, and calcium are introduced during solid-phase synthesis, and multi-element doping is performed at both the A-site and B-site to substitute into the BaTiO3 material. After blending and high-temperature sintering, the finished product is obtained. The method features simple preparation conditions, mature processes, low costs, and high reliability. Under the induction of an electrical field, a large entropy change and strong electrocaloric effect are generated.

The present invention discloses modified barium titanate ceramic particles with a low Curie temperature and low room temperature resistivity, as well as a preparation method and application thereof. The modified barium titanate ceramic particles with a low Curie temperature and low room temperature resistivity disclosed in the present invention have a room temperature resistivity between 0.6 and 4 Ω·cm and a Curie temperature between 45 and 55°C. They are prepared from the following raw materials: 2 to 3 mol of barium titanate hydrothermal powder, 0.2 to 0.8 mol of a Curie temperature peak shifter, 0.001 to 0.01 mol of a rare earth oxide, 0.1 to 0.4 mol of silicon dioxide powder, 0.2 to 0.5 mol of titanium dioxide powder, and 0.2 to 0.5 mol of nickel metal powder. The modified barium titanate ceramic particles with a low Curie temperature and low room temperature resistivity of the present invention can be used in the recycling of waste lithium batteries, can achieve rapid discharge and prevent thermal runaway, and have sufficient mechanical strength and are reusable.