58 results about "Double perovskites" patented technology

The invention discloses a double-perovskite thin film material, a preparation method thereof and a double-perovskite solar cell, and relates to the technical field of perovskite materials. The double perovskite thin film material comprises A2BCX6 type double perovskite, A is an alkali metal cation, B is a monovalent metal cation, C is a trivalent metal cation, and X is a halogen anion; the additive is a compound comprising a benzene ring and at least two sulfydryl substituted at different positions of the benzene ring. According to the embodiment, the composite center of the interior and interface of the double-perovskite thin film material can be reduced, the nucleation density in the preparation process of the double-perovskite thin film is reduced, the double-perovskite film layer has high crystallinity and larger grain size, the grain boundary in the film layer is reduced, the grain boundary defect is passivated, and the performance of the double-perovskite thin film is improved. And the photoelectric conversion efficiency of the solar cell containing the double perovskite thin film material can be improved.

The invention relates to an A-site high-entropy double perovskite anode material and a preparation method and application thereof. The chemical general formula of the anode material is (Ln < 1 > < 0.2 > Ln < 2 > < 0.2 > Ln < 3 > < 0.2 > Ln < 4 > < 0.2 > Ln < 5 > < 0.2 >) A 'B2O5 + delta (wherein delta is greater than or equal to 0 and less than or equal to 1). Wherein Ln1 to Ln5 are five different lanthanide rare earth elements and jointly occupy the A site, and the A site elements are any five of Sm, Pr, Nd, La, Gd, Eu, Er, Dy, Te, Yb, Y and Sc; the A'site is composed of any two elements of Ba, Sr and Ca; and the B site is Co. According to the invention, the double perovskite structure can be effectively stabilized, the number of catalytic active sites of an OER reaction is increased, the TEC of a cathode is effectively reduced, the electro-catalysis ORR reaction activity is increased, the performance of hydrogen production by electrolysis of water of a single cell is improved, and the output stability of the cell is effectively enhanced.

This invention belongs to the field of solid oxide fuel cell technology, specifically relating to a method for preparing and applying a highly catalytically active and stable high-entropy double perovskite direct ammonia solid oxide fuel cell anode. The anode material is characterized by having the general chemical formula Sr₂Fe₃. x Sn y Co y Nb y Zr y Mo z O 6‑δ Wherein, 0.75≤x≤1, 0.15≤y≤0.25, 0.25≤z≤0.4, 0≤δ≤1, and δ represents the oxygen vacancy content. The material of this invention exhibits excellent catalytic activity and outstanding stability, effectively solving the Sr₂Fe₂O₃ problem. 1.5 Mo 0.5 O6 anode material exhibits structural instability at high temperatures (above 800℃) and tends towards perovskite-like Sr3FeMoO2. 6.5 The problem of transformation. The material of this invention and the electrolyte material La. 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 2.85 The material exhibits good chemical compatibility, and solid oxide fuel cells fabricated using this invention demonstrate excellent electrochemical performance and superior long-term stability under both H2 and NH3 conditions. The material is simple to prepare, possesses excellent performance, and has broad application prospects.

This invention belongs to the field of photocatalytic materials and new energy technology, and discloses a method for preparing a Rh-modified Cs₂AgBiBr₆ / CdS heterojunction photocatalyst. The method includes: preparing Cs₂AgBiBr₆ nanoparticles via antisolvent precipitation, preparing CdS nanorods via hydrothermal method, subsequently constructing a heterojunction through in-situ growth, and loading a Rh co-catalyst using photoreduction. This invention effectively overcomes the technical bottleneck of structural instability of traditional perovskites in polar solvents by introducing a Cs₂AgBiBr₆ double perovskite with a rigid lattice structure. Experiments show that the catalyst retains its structural integrity after immersion in ethanol for 168 hours and under different atmospheres, and exhibits excellent performance in the photocatalytic dehydrogenation of ethanol, with a hydrogen production rate as high as 49.15 mmol·g⁻¹. ‑1 ·h ‑1 The apparent quantum efficiency at 420 nm is 22.5%, and it remains stable during a 60-hour continuous reaction. This invention provides a new strategy for developing efficient and stable lead-free perovskite photocatalytic systems.

The invention belongs to the field of photocatalysis, and particularly discloses a perovskite composite photocatalyst for photocatalytic ethanol dehydrogenation and application. The composite photocatalyst takes a CdS nanorod as a carrier, a Cs2AgBiBr6 double perovskite active component formed by CsBr, AgBr and BiBr3 precursors is loaded on the surface of the CdS nanorod through a vacuum in-situ growth method, and a Pt, Rh or Ni metal cocatalyst can be further loaded. The method comprises the following steps: dispersing a CdS nanorod and a perovskite precursor in a mixed organic solvent, carrying out vacuum freezing-air exhaust circulation treatment, and removing the solvent under a heating condition to prepare the composite photocatalyst. When the photocatalyst is used for an ethanol photocatalytic dehydrogenation reaction under an anaerobic condition, hydrogen, acetaldehyde and acetal can be efficiently generated under the irradiation of visible light. According to the method, the photo-generated charge separation efficiency and the reaction stability are remarkably improved, and a new way is provided for ethanol high-valued conversion.

Aspects of the present disclosure generally relate to a new class of compositions utilized for detecting short-wave infrared (SWIR) light, to devices including the compositions, and to photodetectors including the compositions. Aspects of the present disclosure also generally relate to processes for forming the compositions, the devices, and the photodetectors. In an aspect, a process for forming a SWIR device is provided. The process includes forming a precursor solution comprising: a first compound (AX), a second compound (BX), a third compound (CX3), a nitrogen-containing compound, and a solvent. The process further includes: dispersing the precursor solution on a substrate surface of a substrate and annealing the dispersed precursor solution on the substrate at an annealing temperature that is from about 100° C. to about 300° C. to form a film composition comprising: the nitrogen-containing compound or ion thereof; and a lead-free double perovskite represented by Formula (I): A2BCX6 (I).

The invention relates to the technical field of lithium ion battery materials, and discloses a double perovskite oxide coated ternary positive electrode material as well as a preparation method and application thereof. The invention provides a double-perovskite oxide coated ternary positive electrode material, which comprises a nickel manganese lithium cobalt oxide ternary positive electrode material and a coating layer coated on the surface of the nickel manganese lithium cobalt oxide ternary positive electrode material, the coating layer comprises a double-perovskite oxide, and the double-perovskite oxide comprises La2NiMnO6. The double perovskite oxide coated ternary positive electrode material provided by the invention has excellent cycle performance, excellent rate capability and voltage stability. The invention also provides a preparation method of the double perovskite oxide coated ternary positive electrode material, the preparation method is mild in condition and easy to amplify, and a solid technical basis is provided for manufacturing the positive electrode material of the lithium ion battery with high performance and long service life.

The invention discloses a Ti / Nb co-doped layered double perovskite type oxygen electrode material and a preparation method and application thereof, the chemical general formula of the Ti / Nb co-doped layered double perovskite type oxygen electrode material is PrBaCo < 2-x-y > Ti < x > Nb < y > O < 5 + delta >, x is less than or equal to 0.2, 0 lt; y is less than or equal to 0.2, and delta is oxygen vacancy content. According to the Ti / Nb co-doped layered double perovskite type oxygen electrode material prepared by the method, on the basis of high intrinsic activity of PrBaCo2O5 + delta, through doping of Ti / Nb double elements, the proton conductivity of the oxygen electrode material is improved, element segregation is inhibited, and the thermal expansion coefficient is reduced, so that the oxygen electrode material has high electrocatalytic activity and operation stability.

The invention provides an application of a two-dimensional rare earth double perovskite material in preparation of a memristor, and relates to the technical field of memristors, the chemical general formula of the two-dimensional rare earth double perovskite material is (R3HQ) 4CeRb (NO3) 8, wherein the (R3HQ) 4CeRb (NO3) 8 is a monoclinic system, and the polar point group of the (R3HQ) 4CeRb (NO3) 8 is P21; and R3HQ is an (R)-3 hydroxyl quinuclidine ring organic cation. Two-dimensional rare earth double perovskite (R3HQ) 4RbCe (NO3) 8 is used as an active layer, and a memristor device is directly constructed. The memristor shows bipolar switching characteristics without electroforming, has long-term stability and good flexibility, and can bear hundreds of bending cycles.

The application discloses a lead-free halogen double-perovskite full-spectrum fluorescent powder and a preparation method thereof. 1‑x Cl6:xPt 4+ Wherein, M is one of Zr, Sn and Hf, 0

To specifically provide a double perovskite material, a manufacturing method of the same, and a reversible proton ceramic electrochemical battery, while relating to a field of the reversible proton ceramic electrochemical battery.SOLUTION: A formula of a double perovskite material is PrBa0.9Cs0.1Co2O6-δ, where δ represents an oxygen vacancy content. The present invention further provides a manufacturing method of the double perovskite material, and a reversible proton ceramic electrochemical battery containing the double perovskite material. The double perovskite material in which Cs+ is doped, that is provided by the present invention exhibits excellent stability, relatively low polarization impedance, and relatively high ORR / OER activation. The reversible proton ceramic electrochemical battery provided by the present invention exhibits excellent stability, electrocatalytic activation, and electrochemical performance.SELECTED DRAWING: Figure 11

The invention belongs to the technical field of detection materials, and relates to a double-perovskite-based luminescent material, a preparation method thereof and application of the double-perovskite-based luminescent material in luminescent imaging or anti-counterfeiting. The molecular formula of the double-perovskite-based luminescent material is Cs2NaCrCl6: Tm < 3 + > / Yb < 3 + >, the molar doping concentration of Tm < 3 + > is 0.5-5%, and the molar doping concentration of Yb < 3 + > is 2-80%. The preparation method comprises the following steps: dissolving cesium chloride, sodium chloride, chromium chloride, thulium chloride and ytterbium chloride in water according to a stoichiometric ratio, uniformly mixing, carrying out a solution synthesis reaction, and evaporating to remove a solvent, thereby obtaining the product. The double-perovskite-based luminescent material provided by the invention can generate light with different colors, can realize multiple anti-counterfeiting, is simple in preparation process and low in cost, and is beneficial to realizing industrial large-scale production.

The invention discloses a hydrogen-based superconducting material Na2GaCuH6 with a double perovskite structure under normal pressure and a preparation method of the hydrogen-based superconducting material Na2GaCuH6. The material has an Fm-3m space group, the lattice constant is calculated and predicted through the first principle, and the material has the superconducting transition temperature of 42.04 K under the normal pressure condition. The material is composed of four common elements of Na, Ga, Cu and H, and the cost is low; the double perovskite structure is stable in thermodynamics and dynamics under normal pressure; the electro-acoustic coupling constant lambda is approximately equal to 0.98, and medium-intensity electro-acoustic coupling is achieved. Compared with an existing high-voltage hydride superconductor, the material can work without high-voltage equipment, and the preparation and application cost is greatly reduced; compared with a traditional normal-pressure superconductor, the superconductor has a higher Tc value. The material can be applied to the fields of low-temperature superconducting devices, superconducting magnets, quantum computing and the like, and has important scientific research value and application prospect.

The invention relates to the technical field of superconducting materials, and discloses a multi-element rare earth barium copper oxide high-temperature superconducting thin film and a preparation method thereof. In order to solve the technical problems that the pinning effect of an artificial magnetic flux pinning center of a high-temperature superconducting material is poor and the critical current density under a high magnetic field is low, the rare earth barium copper oxide is prepared by co-doping at least three rare earth elements at a rare earth site; an artificial magnetic flux pinning center of a perovskite oxide BaZrO3 and a double perovskite oxide Ba2YNbO6 is introduced into the rare earth barium copper oxide, and a multi-scale pinning system from the atomic scale to the nanoscale is formed in the superconducting thin film through atomic scale mismatch and introduction of the artificial magnetic flux pinning center; effective pinning of magnetic flux vortexes of different states and different sizes is achieved, and therefore the critical current density of the high-temperature superconducting material under the low-temperature high magnetic field is effectively improved finally.

The invention discloses a Cs2KYCl6-doped rare earth-based double perovskite WLED (White Light Emitting Diode) luminescent material, belongs to the technical field of luminescent materials, and is used for solving the technical problem that the luminous efficiency, warm white color product stability and reliability in a humid and hot environment of the WLED luminescent material in the prior art need to be further improved. The invention relates to a Cs2KYCl6 doped rare earth-based double perovskite WLED (White Light Emitting Diode) luminescent material, the WLED luminescent material is a luminescent nanosheet coated with polysiloxane, and the luminescent nanosheet has a chemical general formula Cs2K (Y < 1-x > Lnx) Cl6. According to the invention, the composition and doping amount of rare earth elements are optimized, the crystal growth process is controlled, and the luminescent nanosheets are compactly coated with the fluorine-containing polysiloxane sol, so that the high luminous efficiency of the WLED luminescent material and the stability of a warm white color product are effectively improved, and the reliability of the WLED luminescent material in a humid and hot environment is also improved.

The invention provides a lead-free double-perovskite solar cell and a preparation method and a characterization method thereof, and the method employs p-aminobenzoate molecules to modify lead-free double-perovskite CsAgBiBrcrystals, forms a perovskite thin film with a flat and uniform surface, improves the charge transmission and exchange efficiency at the surface of a perovskite light absorption layer, and at the same time, improves the photoelectric conversion efficiency of the perovskite light absorption layer. Functional groups in the p-aminobenzoate can be selectively coordinated with two sublattices in the double inorganic perovskite CsAgBiBr, so that ordered arrangement of the sublattices is promoted, and the photoelectric conversion efficiency and the stability of the lead-free double perovskite device are effectively improved. In addition, the CsAgBiBr film before and after aminobenzoate molecule modification is subjected to in-situ characterization through a Raman spectrum technology, and the optimization degree of the film is monitored in real time; meanwhile, in combination with electrochemical test data, a technical path for modifying and regulating the performance of the CsAgBiBr perovskite solar cell by the p-aminobenzoate is constructed. The technology provides an important research strategy and theoretical technology for performance improvement and quality control of the CsAgBiBr lead-free double perovskite-based photoelectric device.

The invention discloses development and application of a high-entropy B-bit double-perovskite electromagnetic wave absorbent, and belongs to the field of electromagnetic wave absorbing materials in material science and engineering technologies. The chemical formula of the high-entropy double perovskite material prepared by the invention is La2MRuO6, wherein the M site comprises Co, Ni, Mg, Zn and at least one of other elements such as Mn, Fe, Cu, Na, Li and the like. Compared with traditional medium-entropy and low-entropy perovskite materials, the perovskite material has the advantages of high dielectric loss, magnetic loss, low impedance, high wave-absorbing performance and the like. The tunable local electronic structure is provided through the high-entropy effect, and the excellent performance of the high-entropy material in the application of electromagnetic wave absorption is achieved. The method has the advantages of being simple in process, environmentally friendly, high in wave absorbing efficiency, wide in wave absorbing frequency band and the like.

The application discloses a perovskite cathode catalytic material for hydrogen production by solid oxide ammonia electrolysis and preparation and application thereof. 1.5‑x Co x Mo 0.5 O6 (0≤x≤0.3). The cathode prepared by the material can operate under medium-high temperature working conditions, and hydrogen reduction occurs in the ammonia electrolysis process, cobalt-iron alloy is generated and anchored in the layer perovskite Sr3Fe 2‑x‑ y Co x Mo y O7 (0≤x≤0.3, 0≤y≤0.3) surface, which makes the cathode interface have more content of low-valence state ions, can provide acceptor electrons for water dissociation, enhances the adsorption and desorption capacity of the cathode interface to water vapor, and the surface alloy also provides more active sites for water dissociation, and thus can be used for hydrogen production by solid oxide ammonia electrolysis.

The invention belongs to the technical field of solid oxide batteries, and discloses a B-site bismuth-doped oxygen electrode material and a preparation method thereof. The oxygen electrode material is a double perovskite oxide, the chemical formula is PrBa < 0.8 > Ca < 0.2 > Co < 1.5 > Fe < 0.5-x > Bi < x > O < 5 + delta >, x is more than 0 and less than or equal to 0.05, and delta is the content of oxygen vacancies. The oxygen electrode material is prepared through a citrate combustion method, the preparation method has the advantages of being low in sintering temperature and simple and convenient in technological process, and the prepared double perovskite material has high oxygen surface exchange rate and high electrocatalytic activity and has good electrochemical performance and stability. The oxygen electrode material is applied to an oxygen electrode of a solid oxide fuel cell and shows preferential long-term stability, so that the oxygen electrode material has the potential of serving as the oxygen electrode of the solid oxide fuel cell.

This invention belongs to the field of reversible proton ceramic battery technology, and relates to an oxygen electrode material for a three-phase heterointerface reversible proton ceramic battery. The three-phase heterointerface reversible proton ceramic battery oxygen electrode material is a three-phase composite containing A-site defects in double perovskite Pr. 1‑α BaCo2O 5+δ1 (PBC) phase, single perovskite BaPrO 3‑δ2 The invention comprises a (BPO) phase and in-situ desoluble praseodymium oxide nanoparticles; with the total mass percentage of PBC phase, BPO phase, and praseodymium oxide nanoparticles being 100%, the PBC phase accounts for 50-65 wt%, the BPO phase accounts for 33-45 wt%, and the praseodymium oxide nanoparticles account for 1-5 wt%. The three-phase heterogeneous interface oxygen electrode material constructed in situ in this invention exhibits tight coupling and synergistic effects among the three phases, resulting in both a low coefficient of thermal expansion and high catalytic activity. This oxygen electrode material demonstrates excellent electrochemical performance in reversible proton ceramic batteries, whether in fuel cell mode or electrolyzer mode.

This invention relates to a method for preparing double perovskite La2CoFeO6 and its application in degrading odorous pollutants, comprising the following steps: dissolving La(NO3)3·6H2O, Co(NO3)2·6H2O, and Fe(NO3)3·9H2O in a mixed solution of deionized water and ethylene glycol or deionized water and citric acid, adjusting the pH, and then mixing thoroughly; placing them separately in a high-pressure reactor and heating or evaporating the moisture and drying in an oven to obtain precursor powder or dry gel; then calcining at high temperature and cooling to obtain double perovskite La2CoFeO6 powder. The R3c phase La2CoFeO6 material provided in this application, by combining crystal structure regulation with oxygen vacancy defect engineering, establishes a synergistic enhancement mechanism of "structure optimization + defect regulation" for double perovskite materials, significantly improving the photoresponse capability and catalytic performance of the material, providing a new technical path and material design idea for the design of subsequent high-performance photocatalysts for odor pollution control.

The invention belongs to the technical field of photocatalytic functional materials, and particularly relates to a double-perovskite photocatalyst as well as a preparation method and application thereof. The preparation method specifically comprises the following steps: by taking La (NO3) 3.6 H2O, Ba (NO3) 2, Co (NO3) 2.6 H2O and citric acid as raw materials, adding ethanol as a dispersing solvent, and sequentially carrying out ball milling, drying and calcining treatment, so as to obtain the La (2-x) BaxCo2O6 double-perovskite type photocatalyst. The preparation method is simple and easy to operate, and large-scale production can be realized. The obtained double perovskite type photocatalyst La2-xBaxCo2O6 can effectively degrade phenol in wastewater under visible light irradiation and a peroxymonosulfate (PMS) system, the degradation rate reaches 100% within two minutes, and the double perovskite type photocatalyst La2-xBaxCo2O6 has wide application value in the field of phenol wastewater treatment.

The invention discloses an ionic liquid gating method for double perovskite oxide film hydrogen ion doping, and belongs to the field of film material ion doping. The oxide film serves as a working electrode, ionic liquid is clamped between the oxide film and the top electrode, an electrochemical gating structure is formed, hydrogen ions are driven by an external electric field to migrate into the film from the ionic liquid, and therefore controllable introduction of the hydrogen ions into the film is achieved. Compared with the traditional methods of high-temperature atmosphere treatment, acid treatment, ion implantation and the like, the method can realize effective hydrogen ion doping under the conditions of room temperature and low voltage, and avoids complex process and material damage. The method is simple and convenient in process, high in speed and obvious in effect, and reversible injection and extraction of hydrogen ions are realized by accurately controlling the magnitude and polarity of the applied voltage in the doping process. The method is suitable for various transition metal oxide thin film systems, the lattice constant, the electronic structure and the electrical performance of the transition metal oxide thin film systems can be remarkably adjusted, and potential device application value is achieved.

This invention relates to the field of luminescent materials technology, and more specifically, to molybdenum-doped fully inorganic hole-ordered double perovskites, their preparation methods, and applications. The first aspect of this invention provides three types of molybdenum-doped fully inorganic hole-ordered double perovskites: tetravalent molybdenum-doped, pentavalent molybdenum-doped, and co-doped with tetravalent and pentavalent molybdenum, with the chemical formulas Cs₂Sn₂, respectively. 1‑x Cl6:xMo 4+ Cs2Sn 1‑y (O y Cl 6‑y ):yMo 5+ and Cs2Sn 1‑a‑b (O b Cl 6‑b ):aMo 4+ ,bMo 5+ The second aspect of this invention provides methods for preparing three types of molybdenum-doped fully inorganic hole-ordered double perovskites: tetravalent molybdenum-doped, pentavalent molybdenum-doped, and co-doped with tetravalent and pentavalent molybdenum. The third aspect provides applications of these three types of molybdenum-doped fully inorganic hole-ordered double perovskites in product testing, anti-counterfeiting, safety monitoring, non-destructive analysis, light-emitting LEDs, solar cells, temperature detectors, multispectral imaging, ultra-wideband light sources, or broadband photodetectors. The fourth aspect provides an optoelectronic device in which the luminescent material is this molybdenum-doped fully inorganic hole-ordered double perovskite.

The invention relates to the technical field of magnetic recording media and magnetic multifunctional materials, in particular to double perovskite oxide ceramic with an exchange bias effect and a preparation method of the double perovskite oxide ceramic. The chemical formula of the ceramic is Nd2-xSrxCoMnO6, the molar doping amount x of Sr < 2 + > is more than or equal to 0.0 and less than or equal to 0.5, and the ceramic has a single-phase orthogonal structure. The preparation method comprises the following steps: proportionally mixing the raw materials, and sintering in three stages to obtain the ceramic. When Sr < 2 + > is not doped, the oxygen vacancy defect causes a spin structure change and causes an exchange bias effect, under a 1kOe cooling magnetic field, the exchange bias field is 2.8 kOe, and the exchange bias does not have a magnetic exercise effect; when Sr < 2 + > is doped, the crystal structure and the spin structure change, the exchange bias field is 2.1-3.6 kOe, and the Curie temperature is 128-141K. The ceramic is stable in performance, the preparation process is simple and easy to control, and the ceramic is suitable for industrial production and suitable for the field of electronic components such as high-density magnetic storage.

The invention discloses a preparation method and application of a high-efficiency optical communication waveband luminescent material, and belongs to the field of luminescent material preparation, the chemical general formula of the luminescent material is as follows: the luminescent material comprises a matrix with a double perovskite structure and ions doped in the matrix; wherein the luminescent material has a characteristic emission peak at the wave band of 1500 to 1600 nm under the excitation of ultraviolet light. The process is simple to operate, good in reproducibility, low in energy consumption and extremely easy for large-scale production.

The invention relates to the technical field of perovskite thin films, and discloses a low-voltage high-stability memristor based on lead-free double perovskite and a neuromorphic calculation application thereof.The low-voltage high-stability memristor comprises a top electrode, a thin film and a bottom electrode which are stacked in sequence, powder is dissolved in DMSO, a 0.4 M precursor solution is formed and deposited on an FTO glass substrate through a two-step spin-coating method, and the memristor is obtained. And annealing at a set temperature for 20 minutes. The memristor still keeps stable resistance switch performance after being stored for 30 days under the unpackaged condition, the stability bottleneck of perovskite materials in practicability is broken through, the operation voltage is reduced to + 0.4 V / 0.3 V, power consumption is remarkably reduced, the memristor is more suitable for low-power-consumption scenes such as the Internet of Things and mobile equipment, and the application range is wide. By adopting the spin-coating process without anti-solvent instillation or inert gas protection, high-quality thin film preparation can be realized in dry air, the equipment complexity and the manufacturing cost are reduced, and the process feasibility and repeatability are improved.

The invention provides a composite lithium-rich manganese-based material and an in-situ coating preparation method thereof, the composite lithium-rich manganese-based material is an AMnB2O6 coated composite lithium-rich manganese-based material, the AMnB2O6 has a double perovskite structure, and the mass of an AMnB2O6 coating layer is 0.5%-5% of the mass of the composite lithium-rich manganese-based material; the chemical formula of the composite lithium-rich manganese-based matrix material is Li < 1.2 > Ni < x > Co < y > Mn < z > O < 2 >. A uniform, continuous and chemically stable AMnB2O6 coating layer is formed on the surface of the positive electrode material, so that the redox activity of oxygen anions is effectively inhibited, electrolyte decomposition and harmful phase change are reduced, and the structural stability and cycle performance of the material are remarkably improved. The positive electrode material disclosed by the invention is particularly suitable for a high-energy-density lithium ion battery, and can meet the requirements of an electric automobile and a large-scale energy storage system on long cycle life and high safety.

This invention discloses a multi-step high-entropy high-enthalpy phase transition hybrid double perovskite material and its preparation method. The preparation method includes the following steps: 1) Weigh at least one of 1,3-propanediamine, N-methyl-1,3-propanediamine, 1,3-diamino-2-propanol, ethylenediamine, N-ethylethylenediamine, and N-(2-hydroxyethyl)ethylenediamine, as well as a salt containing M1, a salt containing M2, and formic acid as raw materials according to stoichiometric ratio; 2) Add the above raw materials to a reaction vessel lined with polytetrafluoroethylene and mix evenly; 3) Seal the reaction vessel and heat it at a constant temperature of 80-110℃ for 36-72h; 4) Cool naturally to room temperature, collect the product, wash and dry it to obtain a material with the chemical formula [A]2[M1M2(HCOO)6]. This material achieves multi-step reversible high-entropy and high-enthalpy phase transitions through heterovalent bimetallic synergy and flexible cyclic ammonium cation design. It also features dielectric response and low-temperature photoluminescence. The phase transition temperature can be tuned to room temperature and near room temperature range, effectively solving the problems of limited phase transition steps, low entropy and enthalpy changes, and poor performance synergy of existing materials.

The invention discloses a high-performance p-type transparent conductive material based on hydration regulation and a preparation method thereof, and belongs to the technical field of photoelectric materials. The preparation method comprises the following steps: uniformly mixing a cesium source, a bismuth source or antimony source, a zinc source or antimony source, a ligand and a solvent, and performing vacuum drying under a stirring condition; and heating, rapidly injecting a chlorine source or a bromine source, immediately immersing into an ice-water bath after the reaction is finished, cooling to room temperature, adding ethyl acetate into the reaction liquid after the reaction is finished, centrifuging, resuspending, precipitating, carrying out secondary centrifugation, and collecting the supernate, thereby obtaining the high-performance p-type transparent conductive material Cs4AB2C12. The p-type transparent conductive material based on layered double perovskite provided by the invention solves the problems of low conductivity, limited light transmittance and insufficient stability of the existing p-type transparent conductor. Controllable transformation of the morphology and the electronic structure of the induction material is regulated and controlled through hydration, so that the charge transfer performance is remarkably improved. While high light transmittance is maintained, electrical and optical properties superior to those of a traditional p-type transparent conductor are obtained.