11results about How to "High polarization" patented technology

The invention discloses a high-energy-storage-density anti-ferroelectric ceramic material and a preparation method thereof. The general chemical formula is (Pb < 0.98 > La < 0.02 >) (Zr < 0.7 > Sn < 0.3 >) < 0.995 > O < 3-x > wt% Al < 2 > O < 3 >, x is smaller than or equal to 0.7, Al2O3 is a sheet-shaped template, the Al2O3 sheet-shaped template is directionally arranged in the anti-ferroelectric ceramic material along the same direction through a tape casting preparation process, and the Al2O3 sheet-shaped template is regulated to be parallel to a test electrode through polishing and metal spraying on the upper surface and the lower surface parallel to the Al2O3 sheet-shaped template. According to the anti-ferroelectric ceramic material, the Al2O3 sheet-shaped template and the test electrode are arranged in parallel, so that the Al2O3 sheet-shaped template effectively disperses an applied electric field in the whole anti-ferroelectric ceramic material matrix, non-uniform distribution of a local electric field is reduced, improvement of the breakdown strength of the anti-ferroelectric ceramic material is facilitated, and the energy storage density of the anti-ferroelectric ceramic material is further improved.

The invention discloses a heat treatment method of high-polarization-intensity bismuth ferrite-lead titanate-barium zirconate titanate based ferroelectric ceramic, which comprises the following steps: arranging an electrode on the surface of a bismuth ferrite-lead titanate-barium zirconate titanate based ferroelectric ceramic sintered body, and then putting the sintered body into a rapid annealing furnace; the preparation method comprises the following steps: heating to 550-650 DEG C from room temperature at a heating rate of 5-80 DEG C / s, carrying out heat preservation for 45-75 seconds, carrying out first rapid annealing, and cooling to room temperature at a cooling rate of 250-350 DEG C / s, thereby obtaining the bismuth ferrite-lead titanate-barium zirconate titanate based ferroelectric ceramic. The heat treatment method provided by the invention can rearrange defects in the ceramic, increase domain conversion switches, improve the performance of the ceramic, and improve the performance of the ceramic. Furthermore, the ferroelectric piezoelectric property of the polarized BF-PT-BZT ceramic is greatly improved, and meanwhile, the polarized BF-PT-BZT ceramic has high Curie temperature.

The present invention belongs to the technical field of functional ceramics, and discloses a high energy storage lead-free relaxor ferroelectric thick film ceramic and its preparation method and application. The chemical formula of the lead-free relaxor ferroelectric thick film ceramic is (Bi 0.5‑0.5x Na 0.5‑0.5x La x )(Ti 1‑x Mg 0.66x Ta 0.33x )O3, x = 0.24. Since multi-ion doping increases the relaxation degree, the dielectric temperature and frequency stability are enhanced, and the energy storage efficiency is improved. In addition, wide bandgap oxides such as MgO (~7.7eV) and Ta2O5 (~4eV) can also increase the breakdown field strength of relaxor ferroelectric thick film ceramics. At the same time, the tape casting process is used to reduce the thickness of the ceramic and further increase the breakdown field strength. The lead-free relaxor ferroelectric thick film ceramic can be used in power pulse devices.

The invention discloses a preparation method of a bismuth ferrite-lead titanate-barium zirconate titanate-based ferroelectric ceramic with high polarization strength. The method comprises the following steps: preparing various oxide raw materials according to the chemical formula of the bismuth ferrite-barium titanate ceramic-based ferroelectric ceramic, mixing to obtain a mixed powder, pre-sintering the mixed powder to obtain a pre-sintered powder, granulating the pre-sintered powder to obtain a granulate, pressing the granulate to obtain a green body, debinding and sintering the green body to obtain a sintered ceramic, and annealing the sintered ceramic to obtain the bismuth ferrite-lead titanate-barium zirconate titanate-based ferroelectric ceramic. The sintered ceramic is annealed by sintering the sintered ceramic. After the annealing, defect dipoles generated by the volatilization of Pb and Bi in the ceramic are rearranged under the action of a temperature field, and a relaxor ferroelectric-ferroelectric phase transition occurs in the ceramic phase, which is reflected in the hysteresis loop as the waist of the loop is opened and the rectangularity is increased, and the bipolar strain curve is transformed from a bud type to a butterfly type typical of ferroelectrics, and the ferroelectricity of the ceramic is further greatly improved.

The present invention discloses a battery separator capable of in-situ regulating polarization strength, and a preparation method and application thereof, wherein a solution containing polyvinylidene fluoride-based copolymer powder is coated on the surface of a base film to obtain a separator having a polymer coating on the surface; a volatile polar solvent is then sprayed on the surface of the polymer coating, and the polar solvent is evaporated to obtain the separator. The battery separator comprises a base film and a PVDF-based ferroelectric polymer coating, wherein the proportion of the β phase in the entire PVDF crystalline phase reaches more than 80%, and the PVDF is a hollow network structure, the coating has a porosity of 20% to 80%, and a thickness of 1 to 10 μm. It has excellent ferroelectric and piezoelectric properties, and when used as a lithium battery separator, it can significantly improve the overall rate capacity and cycle stability of the battery. The preparation method is simple, low-cost, energy-saving and environmentally friendly, and suitable for industrial production.

The invention discloses a dielectric material for a high-dielectric constant, high-resistance and low-loss pulse power type capacitor and a preparation process, the dielectric material takes (Sr0.7 BaxMg (0.3-x) (Ti0. 8RuyTe0.2-y) O3 as a base material, and is added with the following components: La3 (SbzCe1-z) Zr3O12, Ba (Zn1 / 6Nb1 / 3) (B2O4) 2, MnCO3, MnO2 and Li2SiO3, x is more than 0 and less than 0.3, y is more than 0.1 and less than 0.2, and z is more than 0.7 and less than 1.0, Ru and Te elements are added in the process of manufacturing a main base material of the pulse power type ceramic dielectric material provided by the invention to prepare (Sr0.7 BaxMg (0.3-x) (Ti0. La3 (SbzCe1-z) Zr3O12 and Ba (Zn1 / 6Nb1 / 3) (B2O4) 2 synthesized by a solid phase method are added, and the prepared dielectric material has excellent electrical properties of high dielectric constant, high resistance and low loss in the presence of a trace Li element by adjusting the proportion of Mn < 2 + > / Mn < 4 + >, and a capacitor made of the dielectric material has excellent bias characteristic, stable charge and discharge performance and relatively large discharge current, and can be applied to the field of capacitors. The ceramic capacitor is suitable for pulse power type ceramic capacitors.

The invention provides a lead-based antiferroelectric / relaxor ferroelectric composite ceramic material and a preparation method and application thereof.The lead-based antiferroelectric / relaxor ferroelectric composite ceramic material comprises an antiferroelectric phase material and a relaxor ferroelectric phase material, the antiferroelectric phase material is Pb < 0.94 > La < 0.04 > (Zr < 0.84 > Sn < 0.15 > Ti < 0.01 >) O3, and the relaxor ferroelectric phase material is 0.8 Ba (Zr < 0.1 > Ti < 0.9 >) O < 3 >-0.2 Bi (Zn < 2 / 3 > Ta1 / 3) O3; the nominal chemical formula of the lead-based antiferroelectric / relaxor ferroelectric composite ceramic material is Pb < 0.94 > La < 0.04 > (Zr < 0.84 > Sn < 0.15 > Ti < 0.01 >) O < 3 > / 0.8 Ba (Zr < 0.1 > Ti < 0.9 >) O < 3 >-0.2 Bi (Zn < 2 > / 3 > Ta1 / 3) O < 3 >; the mass percent of the relaxor ferroelectric phase material relative to the antiferroelectric phase material is x, and x is more than 0 and less than or equal to 4wt%.

The application discloses a preparation method of an AlN-based ferroelectric device, which comprises the following steps: firstly, preparing an AlN-based ferroelectric film through magnetron sputtering, and constructing a metal-ferroelectric-metal structure device; and then, annealing under pure nitrogen gas, and then annealing by introducing low-concentration hydrogen gas. The process can effectively passivate defect states in the film, reduce the leakage current, improve the breakdown field strength, simultaneously eliminate the wake-up effect and weaken the cyclic fatigue effect, so that the ferroelectric performance and stability of the device are significantly improved. The method has simple process, is compatible with the existing semiconductor manufacturing process, and has a good application prospect.

The invention provides a sodium niobate-based energy storage ceramic material and a preparation method thereof. The general chemical formula of the ceramic material is (1-x) (0.6 NaNbO < 3 >-0.4 Sr < 0.7 > Bi < 0.2 > Mg < 1 / 3 > Nb < 2 / 3 > O < 3 >)-xBaTiO < 3 > (I), in the formula (I), x is mole fraction, and x is more than or equal to 0.05 and less than or equal to 0.20. The material is prepared by sintering a NaNbO3-Sr0. 7Bi0. 2Mg1 / 3Nb2 / 3O3 substrate material and a BaTiO3 material through a solid-phase reaction method. The (1-x) (0.6 NaNbO3-0. 4Sr0. 7Bi0. 2Mg1 / 3Nb2 / 3O3)-xBaTiO3 ceramic material prepared by the preparation method disclosed by the invention not only has high polarization intensity and high breakdown strength, but also has extremely high energy storage density. The ceramic material is lead-free environment-friendly excellent energy storage ceramic, the performance of the ceramic material is obviously superior to that of other system ceramics, and the application requirements of the ceramic material in the aspects of pulse dielectric capacitors and the like can be met.

A calcium titanate-based dielectric material with high energy storage performance was designed. The chemical formula of this material is Ca. 1‑x Dy x (Ti 1‑y Hf y ) 1‑x / 4 O3-z mol%M, where x=0.005~0.05, y=0.1~0.2, z=0~2, and M is MnO2 or BaCu(B2O5). It is prepared using solid-state reaction and tape casting methods. This invention, based on calcium titanate-based ceramics with high breakdown field strength, employs a series of strategies to improve energy storage performance, including element substitution, doping with sintering aids, and process improvement: partial substitution of Hf elements at the B site increases the band gap; doping with sintering aids improves grain density, both of which enhance the breakdown field strength; the addition of rare earth element Dy enhances the polarization response by introducing defect dipoles; the non-stoichiometric design reduces oxygen vacancy compensation, thereby increasing resistivity; and the tape casting method improves ceramic density and grain uniformity. The final prepared calcium titanate-based energy storage medium ceramic material exhibits good energy storage performance, with Ca... 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The best energy storage performance was achieved in O3-0.5 mol% BaCu(B2O5) ceramics, with a breakdown field strength of 101.90 kV / mm and an effective energy storage density of 10.22 J / cm³. 3 .

The invention belongs to the related technical field of two-dimensional material devices, and discloses a strain-enhanced multi-sensory fusion photoelectric synapse device and a preparation method and application thereof.The photoelectric synapse device comprises an insulating layer, an electrode and a functional layer which are arranged from bottom to top, and the functional layer is made of an in-plane polarization two-dimensional ferroelectric material; tensile strain is applied to the functional layer in the polar axis direction of the functional layer; the photoelectric synaptic device simulates the perception of visual information through the photoconductive effect of the functional layer, and simulates the tactile sense through the tensile strain. The synergistic effect of the photoconductive effect and the tensile strain significantly enhances the persistent photoconductivity (PPC) of the synaptic device, and the enhancement processing of a fingerprint image is realized through the characteristics of the device. Meanwhile, tensile strain is applied along a specific direction, so that the in-plane polarization intensity is remarkably improved, the restriction of a depolarization field is avoided, the stability and the performance of a ferroelectric device are improved, and a new way is provided for improving the performance of a photoelectric synapse device.