US-20260125280-A1 - AEROSOL-BASED HIGH-TEMPERATURE SYNTHESIS OF MATERIALS WITH COMPOSITIONAL GRADIENT

Abstract

A material synthesis method may comprise: obtaining at least one liquid precursor solution comprising one or more solutes determined based on atomic stoichiometry of target particles; adding the at least one liquid precursor solution to an atomizer device; generating at the atomizer device an aerosol; transporting the aerosol to a reactive zone of a predetermined temperature for a predetermined time; and obtaining synthesized particles by evaporating one or more solvents from the aerosol in the reactive zone.

Inventors

• Yiguang Ju
• XiaoFang Yang
• Jingning Shan
• Christopher ABRAM

Assignees

• PRINCETON UNIVERSITY
• HIT NANO, INC.

Dates

Publication Date

20260507

Application Date

20251219

Claims (20)

1. 1 . A material synthesis method, comprising: obtaining at least one liquid precursor solution comprising one or more solutes determined based on atomic stoichiometry of target particles; adding the at least one liquid precursor solution to an atomizer device; generating at the atomizer device an aerosol; transporting the aerosol to a reactive zone of a predetermined temperature for a predetermined time; and obtaining synthesized particles that match the target particles by evaporating one or more solvents from the aerosol in the reactive zone.
2. 2 . The method according to claim 1 , wherein: the at least one liquid precursor solution comprises a metal salt dissolved or diluted in a solvent; the one or more solutes comprise the metal salt; the metal salt comprises at least one of: alkaline metal, transition metal, lanthanide metal or oxygen coordination metal; the solvent comprises at least one of: water, metal alkoxide, one or more hydrocarbon liquids, or one or more alcohol liquids; and a median size of the synthesized particles increases with a molar concentration of the liquid precursor solution.
3. 3 . The method according to claim 1 , wherein: the synthesized particles comprise one or more elements with uniform concentration gradient from surface to center.
4. 4 . The method according to claim 3 , wherein: the one or more solutes are determined based on a solubility of the one or more solutes; and the concentration gradient depends at least on one or more of the solubility of the one or more solutes, an ion diffusion rate of ions in the at least one liquid precursor solution, an ion precipitation rate of the ions in the at least one liquid precursor solution, and a solvent evaporation rate of the at least one liquid precursor solution.
5. 5 . The method according to claim 1 , wherein the synthesized particles are doped with ions of a predetermined molar concentration, wherein the predetermined molar concentration depends at least on a solubility of each of the one or more solutes.
6. 6 . The method according to claim 1 , wherein the transporting the aerosol to a reactive zone of a predetermined temperature for a predetermined time comprises: setting an environment of the reactive zone by setting a combination of a temperature, a flow rate, and a direction of heating gas injected into the reactive zone.
7. 7 . The method according to claim 1 , wherein, before transporting the aerosol to the reactive zone, the method further comprises: transporting the aerosol to a preheating zone; and evaporating at least a portion of the one or more solvents from the aerosol for 0.0-1 seconds by preheating the aerosol at a temperature between 50 o C and 500 o C.
8. 8 . The method according to claim 7 , wherein: preheating the aerosol comprises preheating the aerosol with at least one of: a cool flame, a warm flame, an electrical heating, a combustion heating, or a heat exchange with a recirculated exhaust gas.
9. 9 . The method according to claim 1 , wherein: the reactive zone comprises at least one of: a flame, plasma, furnace, laser heating, or electric heating; the reactive zone is at a temperature of 500-10000 o C and a pressure of 500 mbar - 10 bar; and the evaporating one or more solvents from the aerosol in the reactive zone comprises evaporating one or more solvents from the aerosol for 0.0-1 seconds.
10. 10 . The method according to claim 9 , wherein the flame includes one or more of: a hot flame with a temperature higher than 1200 o C, a warm flame with a temperature between 800 o C and 1200 o C, and a cold flame with a temperature lower than 800 o C.
11. 11 . The method according to claim 1 , wherein: the synthesized particles comprise a metal oxide, a metal fluoride, a metal chloride , a metal sulphide, a metal oxysulphide, a metal silicate, a metal nitrate, a metal acetate, or a metal nitride; and the synthesized particles comprise non-aggregated particles.
12. 12 . The method according to claim 1 , wherein the synthesized particles comprise nickel-cobalt-manganese nano-particles doped with: aluminum ions, antimony ions, tantalum ions, titanium ions, zirconium ions, magnesium ions, cerium ions, fluorine ions, silver ions, oxygen coordination ions, or lanthanide ions.
13. 13 . A material synthesis system, comprising: an atomizer device configured to receive at least one liquid precursor solution and generate an aerosol from the at least one liquid precursor, wherein the at least one liquid precursor solution comprises one or more solutes determined based on atomic stoichiometry of target particles; and a reactor comprising: a preheating zone configured to preheat the aerosol; and a reactive zone configured to evaporate one or more solvents from the aerosol and obtain synthesized particles that match the target particles.
14. 14 . The system according to claim 13 , wherein the reactor is an inwardly off-center shearing jet-stirred reactor.
15. 15 . The system according to claim 13 , wherein the preheating zone and the reactive zone each include one or more pairs of heating gas jets configured to inject a heating gas in one or more directions and mix the injected heating gas and the aerosol for uniform mixing and heating of the aerosol.
16. 16 . The system according to claim 15 , wherein a temperature in the reactor increases along the reactor in a direction from an inlet of the aerosol to an outlet of the aerosol, and an environment of the reactive zone is set by a combination of a temperature, a flow rate, and a direction of the heating gas injected into the reactive zone.
17. 17 . The system according to claim 13 , wherein: the reactor comprises at least one of a flame, plasma, furnace, laser heating, or electric heating; the preheating zone is at a temperature between 50 o C and 500 o C and configured to evaporate at least a portion of the one or more solvents from the aerosol for 0.0-1 seconds; and the reactive zone is configured to evaporate the one or more solvents from the aerosol for 0.0-1 seconds.
18. 18 . The system according to claim 17 , wherein the flame includes one or more of: a hot flame with a temperature higher than 1200 o C, a warm flame with a temperature between about 800 o C and about 1200 o C, and a cold flame with a temperature lower than 800 o C.
19. 19 . The system according to claim 13 , wherein: the one or more solutes are determined based on a solubility of the one or more solutes; and the concentration gradient depends at least on one or more of the solubility of the one or more solutes, an ion diffusion rate of ions in the at least one liquid precursor solution, an ion precipitation rate of the ions in the at least one liquid precursor solution, and a solvent evaporation rate of the at least one liquid precursor solution.
20. 20 . The system according to claim 13 , wherein the synthesized particles are doped with ions of a predetermined molar concentration, wherein the predetermined molar concentration depends at least on a solubility of each of the one or more solutes.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. Patent Application No. 17/438,008, filed on September 10, 2021, titled “Aerosol-Based High-Temperature Synthesis of Materials with Compositional Gradient,” which is a national stage application under 35 U.S.C. §371 of International Application No. PCT/US2020/022147, titled “Aerosol-Based High-Temperature Synthesis of Materials With Compositional Gradient,” filed on March 11, 2020, which is based on and claims priority of benefit to U.S. Provisional Application No. 62/817,453, filed on March 12, 2019, titled “Aerosol-based High-temperature Synthesis of Materials with Compositional Gradient.” The contents of all of the above-referenced applications are hereby incorporated by reference in their entirety. STATEMENT OF U.S. GOVERNMENT SUPPORT This invention was made with government support under Grant No. CMMI-1449314 awarded by the National Science Foundation and Grant No. DE-SC0019893 awarded by the Department of Energy. The government has certain rights in the invention. TECHNICAL FIELD The present invention relates to the field of material science and engineering, and in particular, to high-temperature synthesis of functional nanoparticles with compositional gradient. BACKGROUND Nanostructured materials like nanoparticles and thin films have significant impacts in energy-related and various other applications for their unique properties. Existing methods for producing materials in such applications have various disadvantages. For instance, solid state reactions can be used to produce metal oxide or lithium orthosilicate particles for thermochemical energy storage, but the particle size and shape are difficult to control and subsequent milling/washing steps are required. Wet chemical (co-precipitation) methods can be used to produce battery cathode materials but the processing time is very long (24 hours) and large volumes of toxic waste are produced. Usually the size distribution of the synthesized particles is broad, so separation/sieving (such as by air jet siever) is required, which reduces the product yield. Furthermore, the particle size of particles produced with the above-discussed methods is generally submicron or less, which is unlikely to meet the requirement for particles larger than micron primary structures in battery electrode. Lastly, some aerosol techniques such as spray drying or spray flames use either highly dilute precursor solutions or expensive organometallic precursors to achieve particle size control, which poses as a significant hurdle for mass production. In addition, the lack of precise temperature and vaporization control in the spray flame pyrolysis methods makes it difficult to control particle morphology and concentration distribution inside the particles. Other conventional atomization technologies require high atomization energy and have poor prospects for industrial scale-up due to their high production costs. In addition, with the existing co-precipitation method, it is difficult to accurately control an addition of an element in a small amount due to the large disparity in chemical equilibrium constants of precipitation reactions. It may be also difficult to co-precipitate more than 3 types of ions. For heavy-metal ions to co-precipitate together in the solution, the equilibrium constants of the ions need to be the same, so that the ions can precipitate according to a certain ratio. However, to have the M elements in metal salts such as nitrates (M(NO3)x.yH2O), chlorides (MClx), acetates M(O2C2H3)x·yH2O), etc. precipitate in a certain ratio, the equilibrium constants of the chemical reactions with these metal salts in the solution can vary greatly. So one has to constantly adjust the equilibrium by, for example, changing the pH value, stirring the solution with different strengths, changing the precipitation time by adding additional ligand (e.g., NH3). As such, the control of an actual operation can be very difficult, and the required similar equilibrium constants can be very hard to achieve. In the present disclosure, we present an aerosol based high temperature synthesis method with precise temperature, vaporization, and precipitation control that is not limited by any precipitation equilibrium constants. The method can also accurately control doping of 0.01 %-10 % multiple elements in their concentrations. The method can be used for designing material compositions and structures to improve electrochemical performance, thermal stability, and fire propensity, e.g., capacity, coulombic efficiency, rate performance, cycle-life, oxygen release from charged cathode materials, and spontaneous ignition for the applications in lithium-ion batteries. SUMMARY Systems and methods for synthesizing various materials (e.g., electrochemically, thermochemically, or opto-electronically active materials) are disclosed. Such materials can be used for energy conversion and storage and catalytic chemic