Solid state ultracapacitor

• US 9,881,747 B2
• Filed: 01/29/2016
• Issued: 01/30/2018
• Est. Priority Date: 01/29/2016
• Status: Active Grant

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Rolin, Terry D., Hill, Curtis W.
• Primary Examiner(s): Wilczewski, Mary
• Assistant Examiner(s): Peterson, Erik T
• Application Number:
  US15/010,884
• Publication Number:
  US 20170221648A1
• Time in Patent Office: 732 Days
• Field of Search: None
• CPC Class Codes: C03C 8/20 containing titanium compounds; containing zirconium compounds
• CPC Class Codes: C04B 2235/3215 Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3236 Alkaline earth titanates
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/36 Glass starting materials for making ceramics, e.g. silica glass
• CPC Class Codes: C04B 2235/365 Borosilicate glass
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/6026 Computer aided shaping, e.g. rapid prototyping
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/6584 at an oxygen percentage below that of air
• CPC Class Codes: C04B 2235/6586 Processes characterised by the flow of gas
• CPC Class Codes: C04B 2235/768 Perovskite structure ABO3
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 35/4682 based on BaTiO3 perovskite phase
• CPC Class Codes: C04B 35/62222 obtaining ceramic coatings coating of mortars, concrete, artificial or natural stone or ceramics C04B41/45; laminated ceramic products B32B18/00; coating metallic materials C23; coating of glass C03C17/00, applying ceramic coatings on silicon for semi-conductor purposes H01L
• CPC Class Codes: C04B 35/6262 of calcined, sintered clinker or ceramics
• CPC Class Codes: C04B 35/6264 Mixing media, e.g. organic solvents
• CPC Class Codes: C04B 35/6265 involving reduction or oxidation
• CPC Class Codes: C04B 35/6268 : characterised by the applied pressure or type of atmosphere, e.g. in vacuum, hydrogen or a specific oxygen pressure
• CPC Class Codes: C04B 35/62807 : Silica or silicates
• CPC Class Codes: C04B 35/62813 : Alumina or aluminates
• CPC Class Codes: C04B 35/62884 : by gas phase techniques
• CPC Class Codes: C04B 35/62897 : Coatings characterised by their thickness
• CPC Class Codes: C04B 35/6303 : Inorganic additives
• CPC Class Codes: C04B 35/6316 : Binders based on silicon compounds
• CPC Class Codes: C04B 35/632 : Organic additives
• CPC Class Codes: C04B 35/638 : Removal thereof
• CPC Class Codes: C04B 35/64 : Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: H01G 11/46 : Metal oxides
• CPC Class Codes: H01G 11/56 : Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01G 11/84 : Processes for the manufacture of hybrid or EDL capacitors, or components thereof
• CPC Class Codes: H01G 4/1227 : based on alkaline earth titanates
• CPC Class Codes: H01G 4/30 : Stacked capacitors H01G4/33 takes precedence
• CPC Class Codes: H01G 4/33 : Thin- or thick-film capacitors thin- or thick-film circuits H01L27/00; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor H01L28/40
• CPC Class Codes: H01G 7/06 : having a dielectric selected for the variation of its permittivity with applied voltage, i.e. ferroelectric capacitors electrets H01G7/02
• CPC Class Codes: Y02E 60/13 : Energy storage using capacitors

Abstract

An ink of the formula: 60-80% by weight BaTiO₃ particles coated with SiO₂; 5-50% by weight high dielectric constant glass; 0.1-5% by weight surfactant; 5-25% by weight solvent; and 5-25% weight organic vehicle. Also a method of manufacturing a capacitor comprising the steps of: heating particles of BaTiO₃ for a special heating cycle, under a mixture of 70-96% by volume N₂ and 4-30% by volume H₂ gas; depositing a film of SiO₂ over the particles; mechanically separating the particles; incorporating them into the above described ink formulation; depositing the ink on a substrate; and heating at 850-900° C. for less than 5 minutes and allowing the ink and substrate to cool to ambient in N₂ atmosphere. Also a dielectric made by: heating particles of BaTiO₃ for a special heating cycle, under a mixture of 70-96% by volume N₂ and 4-30% by volume H₂ gas; depositing a film of SiO₂ over the particles; mechanically separating the particles; forming them into a layer; and heating at 850-900° C. for less than 5 minutes and allowing the layer to cool to ambient in N₂ atmosphere.

Claims

1. A method of manufacturing a capacitor comprising the steps of:

a) obtaining BaTiO₃ particles;

said particles having an average grain diameter of 100-700 nm;

b) treating said particles in a first furnace under a mixture of 70-96% by volume N₂ and 4-30% by volume H₂ gas for 60-90 minutes at 850-900°

C.;

c) coating said treated particles with a 3-20 nm thick film of SiO₂ or a 3-10 nm thick film of Al₂O₃ whereby said coated treated particles become agglomerated;

d) separating said coated, treated particles to break up said agglomeration into individual particles;

e) incorporating said separated, coated, treated particles into an ink comprising;

i) 60-80% by weight separated, coated, treated particles;

ii) 5-50% by weight high dielectric constant glass;

said high dielectric constant glass being 0.5-10 μ

m in size;

iii) 0.1-5% by weight surfactant;

iv) 5-25% by weight solvent; and

v) 5-25% by weight organic vehicle;

f) depositing an electrode on a substrate;

said electrode having a resistance between 1 mΩ and

10Ω

;

g) sintering said substrate and electrode;

h) depositing a layer of said ink on said substrate and electrode by a deposition process so that said layer is continuous and has consistent thickness;

i) removing solvent from said layer by drying for 15-30 minutes at 120-150°

C. in air;

j) repeating steps h) and i) until desired thickness is obtained;

k) removing organic binder by exposing said substrate, electrode and ink to the following heating cycle;

i) gradually increasing temperature to 280-350°

C. over 45-90 minutes with a heating rate not exceeding 10-15°

C. per minute

ii) curing at 280-350°

C. for 4-72 hours;

iii) allowing said substrate, electrode and ink to cool to ambient temperature;

l) sintering said at least one layer on said substrate by heating in a second furnace, at 850-900°

C. for less than 5 minutes and allowing it to cool to ambient under N₂ atmosphere;

said N₂ containing less than 25 ppm O₂;

a thickness of said at least one layer being sufficient to produce a sintered layer 10-35 μ

m thick; and

m) depositing a top electrode on said at least one layer;

said top electrode having a resistance between 1 mΩ and

10Ω

.

2. A method as claimed in claim 1 in which said coating process is atomic layer deposition.

3. A method as claimed in claim 1 in which said deposition process of step h) is aerosol jet deposition or silk screening or inkjet printing.

4. A method as claimed in claim 1 in which said separating is performed by a three roll mill or a high shear mixer.

5. A method as claimed in claim 1 in which said high dielectric constant glass is lead-germinate glass or zinc borate glass.

6. A method as claimed in claim 1 in which said surfactant is a phosphate ester.

7. A method as claimed in claim 1 in which said solvent is ester alcohol, terpineol or butyl carbitol.

8. A method as claimed in claim 1 in which said substrate is 0.038-0.040 inch thick and at least 96% pure Al₂O₃, aluminum nitride (AlN), zirconia, beryllium oxide (BeO) or uncured ceramic.

9. A method as claimed in claim 8 in which said uncured ceramic is a mixture of ceramic particles, a binder, a surfactant and a solvent.

10. A method as claimed is claim 9 in which said solvent is 2,2,4-trimethyl-1,3-pentandiol monoisobutyrate, terpineol (C₁₀H₁₈O) or butyl carbitol.

11. A method as claimed is claim 9 in which said surfactant is a phosphate ester.

12. A method as claimed in claim 1 in which said organic vehicle is ethyl cellulose.

13. A method as claimed in claim 1 in which said first furnace is a multizone belt furnace.

14. A method as claimed in claim 1 in which said first furnace is a fluidized bed vertical tube furnace.

15. A method as claimed in claim 1 in which said second furnace is a multizone belt furnace.

16. A method as claimed in claim 1 in which during sintering in step I), time under 600°

C. is 30 minutes maximum;

time under 800°

C. is 20 minutes maximum; and

total time is 60-90 minutes.

17. A method as claimed in claim 14 in which during sintering in step I), the heating rate is 45-55°

C./minute from 300-500°

C.; and

the cooling rate is 45-55°

C./minute from 700-300°

C.