Method of producing high surface area metal oxynitrides as substrates in electrical energy storage

• US 5,980,977 A
• Filed: 12/09/1996
• Issued: 11/09/1999
• Est. Priority Date: 12/09/1996
• Status: Expired due to Term

• Current Assignee: Ultracap Technologies Corp., Yu Cheng Metal Industrial Co., Ltd.
• Original Assignee: Pinnacle Research Institute, Inc.
• Inventors: Ghantous, Dania, Deng, Charles Z., Tsai, Keh Chi
• Primary Examiner(s): UTECH, BENJAMIN L
• Application Number:
  US08/761,837
• Time in Patent Office: 1,065 Days
• Field of Search: 427/79, 427/376.2, 427/377, 427/419.3
• US Class Current: 427/79
• CPC Class Codes: H01G 11/26 characterised by their structure, e.g. multi-layered, porosity or surface features
• CPC Class Codes: H01G 11/46 Metal oxides
• CPC Class Codes: H01G 11/86 specially adapted for electrodes carbonisation or activation of carbon for the manufacture of electrodes H01G11/34
• CPC Class Codes: H01G 9/0032 formation of the dielectric layer
• CPC Class Codes: H01G 9/042 characterised by the material H01G11/22 takes precedence
• CPC Class Codes: H01M 10/0418 with bipolar electrodes
• CPC Class Codes: H01M 4/0402 Methods of deposition of the material
• CPC Class Codes: H01M 4/0438 by electrochemical processing electroless electrochemical plating C23C18/54
• CPC Class Codes: H01M 4/58 of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
• CPC Class Codes: H01M 4/66 Selection of materials
• CPC Class Codes: H01M 50/609 Arrangements or processes for filling with liquid, e.g. electrolytes
• CPC Class Codes: H01M 6/48 with bipolar electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention concerns a process to produce a high surface area niobium oxynitride, tantalum oxynitride, vanadium oxynitride, zirconium oxynitride, titanium oxynitride or molybdenum oxynitride coated substrate for use as an electrical energy storage component in a capacitor or a battery configuration. The process relates to:

(a) coating one or both flat etched surfaces of a solid substrate, in the form of a thin sheet, with a solution or a slurry of a metal halide in a liquid volatile carrier to produce a thin surface film;

(b) contacting the metal halide surface film-carrier coated substrate of step (a) with oxygen, air, or combinations thereof at a temperature to convert the metal halide to metal oxide, respectively, as a thin film and to remove the liquid volatile carrier;

(c) repeating steps (a) and (b) to obtain a desired thickness;

(d) heating the metal oxide film coated substrate of step (c) in oxygen, air or combinations thereof to convert at least about 95% of the metal chloride to metal oxide;

(e) increasing the temperature of the metal oxide coated substrate to elevated temperatures;

(f) contacting the oxide coated substrate produced in step (e) with a nitrogen source selected from excess flowing gaseous ammonia, a mixture of ammonia gas and hydrogen gas, or a mixture of hydrogen gas and nitrogen gas at elevated temperatures to convert about 95% or greater of the oxide coating to the corresponding metal oxynitride on the substrate, which metal oxynitride layer has a high surface area and is electrically conductive; and

(g) cooling to ambient temperature and recovering the high surface area metal oxynitride coated substrate produced in step (f).

Claims

1. A process to produce a high surface area niobium oxynitride, tantalum oxynitride, vanadium oxynitride, zirconium oxynitride, titanium oxynitride or molybdenum oxynitride coated substrate which oxynitride is electrically conducting, which process comprises:

(a) coating one or both flat etched surfaces of a solid substrate, which substrate is in the form of a thin sheet, with a solution or a slurry of a metal halide selected from the group consisting of niobium halide, tantalum halide, vanadium halide, zirconium halide, titanium halide, molybdenum halide, and combinations thereof and a liquid volatile carrier to produce a thin surface film;

(b) contacting the metal halide surface film-carrier coated substrate of step (a) with oxygen, air, or combinations thereof at a temperature of between about 150 and 250°

C. for between about 5 and 60 minutes to convert the metal halide present to metal oxide, as a thin film and to remove the liquid volatile carrier;

(c) repeating steps (a) and (b) to obtain an accumulated thickness of metal oxide coating on the substrate, which accumulated metal oxide coating has a high surface area and the liquid volatile carrier is then removed;

(d) heating the metal oxide film coated substrate of step (c) in an environment selected from the group consisting of oxygen, air and combinations thereof at between about 160 and 240°

C. for between about 1 and 3 hours to convert at least about 95% of any residual metal halide from steps (b), (c) and (d) to metal oxide;

(e) increasing the temperature of the metal oxide coated substrate at a rate of less than about 40°

C. per minute in a nitrogen atmosphere to between about 500 to 800°

C.;

(f) contacting the oxide coated substrate produced in step (e) with a nitrogen source selected from the group consisting of excess flowing gaseous ammonia, an excess flowing mixture of ammonia gas and hydrogen gas, and an excess flowing mixture of hydrogen gas and nitrogen gas at between about 500 and 800°

C. for between 1 and 6 hours which treatment converts about 95% or greater of the metal oxide coating to an oxynitride coating of niobium oxynitride, tantalum oxynitride, vanadium oxynitride, zirconium oxynitride, titanium oxynitride, molybdenum oxynitride layer, and combinations thereof on the substrate, which metal oxynitride layer has a high surface area of between about 10 and 60 m² /g and is electrically conductive; and

(g) cooling to ambient temperature and recovering the high surface area metal oxynitride coated substrate produced in step (f).

2. The process of claim 1 wherein the metal halide is selected from the group consisting of chloride and bromide.

3. The process of claim 2 wherein in step (a) the metal halide is titanium chloride, and in step (g) the metal oxynitiride produced is titanium oxynitride.

4. The process of claim 1 wherein the substrate in step (a) is selected from the group consisting of iron, titanium, molybdenum, aluminum, copper, zirconium, nickel and combinations thereof.

5. The process of claim 1 wherein in step (b) the contacting occurs by dip coating or by spray coating.

6. The process of claim 1 wherein the liquid volatile carrier is selected from the group consisting of ethanol, propanol, butanol, pentanol, hexanol, cycohexanol, diethyl ether, dioxane, tetrahydrofuran, dimethylacetamide, diethylacetamide, acetone, methylethyl ketone, butanone, ethyl acetate, propyl acetate, methylene chloride, chloroform, carbon tetrachloride, benzene, toluene, xylene, and mixtures thereof.

7. The process of claim 6 wherein the liquid volatile carrier is selected from the group consisting of ethanol, propanol, butanol, pentanol and hexanol.

8. The process of claim 6 wherein the liquid carrier is selected from alcohols having 2 to 6 carbon atoms, and water is present at less than 1% by weight.

9. The process of claim 1 wherein:

in step (a) the metal halide is titanium chloride, and the substrate is selected from the group consisting of titanium, molybdenum, iron, aluminum, copper and combinations thereof and the liquid volatile carrier is selected from the group consisting of ethanol, isopropanol and mixtures thereof; and

in step (f) the nitrogen source is flowing ammonia, the temperature is between about 500 and 800°

C. for between about 1 and 6 hours and about 95% to 100% of the titanium oxide is converted to titanium oxynitride.

10. The process of claim 9 wherein the high surface area of titanium oxynitride produced is between about 10 and 60 m² /g, and the temperature in steps (e) and (f) is about 700°

C.

11. The process of claim 1 wherein:

in step (a) the metal halide is titanium chloride and in step (f) titanium oxynitride is formed having a high surface area of between about 20 and 56 m² /g.

12. The process of claim 11 wherein:

in step (a) the liquid volatile carrier is isopropanol;

in step (b) the temperature is between about 150 and 300°

C. and the time is between about 5 and 30minutes;

in step (c) the number of repeating steps is between 10 and 40;

in step (d) the temperature is between about 150 and 300°

C. and the time is between about 2 and 3 hours;

in step (e) the rate of heating is about 40°

C. per minute to 700°

C.; and

in step (f) flowing gaseous ammonia with hydrogen is used at about 700°

C. for between about 3 and 5hours.

13. The process of claim 12 wherein the substrate in step (a) is selected from the group consisting of iron, titanium, molybdenum, aluminum, copper, zirconium, nickel, and combinations thereof.

14. The process of claim 11 wherein the liquid volatile carrier is selected from the group consisting of an alcohol and a mixture of alcohols.

15. The process of claim 1 wherein:

in step (f) titanium oxynitride is formed having a BET specific surface area of between about 50 and 100 m² /g.

16. The process of claim 15 wherein the substrate in step (a) is selected from the group consisting of iron, titanium, molybdenum, aluminum, copper and combinations thereof.

17. The process of claim 1 wherein:

in step (a) the liquid volatile carrier is isopropanol

and the metal halide is titanium chloride;

in step (b) the temperature is between about 150 and 300°

C. and the time is between about 5 and 30 minutes;

in step (c) the number of repeating steps is between 10 and 40;

in step (d) the temperature is between about 150 and 400°

C. and the time is between about 2 and 3 hours;

in step (e) the rate of heating is about 40°

C. per minute to 800°

C.; and

in step (f) flowing gaseous ammonia is used at about 800°

C. for between about 3 and 5 hours.

18. A process to improve the adhesion and cohesion of a high surface area titanium oxynitride, which process comprises:

adding tantalum chloride or tantalum oxide to the titanium oxynitride produced by the process of claim 1 prior to drying in step (b), annealing and pyrolysis at elevated temperatures resulting in tantalum oxide in the product titanium oxynitride, wherein the product has improved adhesion and cohesion.