Electrically-conductive titanium suboxides

• US 4,931,213 A
• Filed: 01/23/1987
• Issued: 06/05/1990
• Est. Priority Date: 01/23/1987
• Status: Expired due to Term

• Current Assignee: Richard B. Cass
• Original Assignee: Richard B. Cass
• Inventors: Cass, Richard B.
• Primary Examiner(s): Barr, Josephine
• Application Number:
  US07/006,119
• Time in Patent Office: 1,229 Days
• Field of Search: 252/502, 252/507, 252/506, 252/520, 501/124, 501/135, 501/99, 423/411, 423/448, 423/447.5, 204/242, 204/291, 204/292, 204/70, 419/11, 419/19, 419/39, 419/45, 419/49, 419/48, 419/57, 419/58, 419/10, 420/417, 75/232, 75/233, 75/234, 75/243
• US Class Current: 252/507
• CPC Class Codes: C04B 35/46 based on titanium oxides or titanates containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49
• CPC Class Codes: C23F 13/12 Electrodes characterised by the material C23F13/16 takes precedence
• CPC Class Codes: C25B 11/04 characterised by the material
• CPC Class Codes: C25C 7/02 Electrodes consumable anodes for the refining the metals C25C1/00 - C25C5/00; Connections thereof
• CPC Class Codes: H01B 1/02 mainly consisting of metals or alloys
• CPC Class Codes: H01B 1/06 mainly consisting of other non-metallic substances
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 2300/0008 Phosphoric acid-based
• CPC Class Codes: H01M 2300/0074 Ion conductive at high temperature
• CPC Class Codes: H01M 4/663 containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
• CPC Class Codes: H01M 4/664 Ceramic materials
• CPC Class Codes: H01M 4/8621 containing only metallic or ceramic material, e.g. made by sintering or sputtering
• CPC Class Codes: H01M 4/8647 consisting of more than one material, e.g. consisting of composites
• CPC Class Codes: H01M 4/9016 Oxides, hydroxides or oxygenated metallic salts
• CPC Class Codes: H01M 4/9091 Unsupported catalytic particles; loose particulate catalytic materials, e.g. in fluidised state
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A process for producing a ceramic material which is electrically conductive by reacting titanium dioxide with intercalated graphite under conditions which effect the reduction of the titanium dioxide, said product comprising an electrically conductive, corrosion-resistant, substoichiometric titanium dioxide combined chemically with an intercalant or residue thereof, for example, a metal such as copper or nickel, and the use thereof in thermal, electrical and electro-chemical applications.

Claims

1. A process for producing a ceramic material which is electrically conductive comprising forming an electrically-conductive, titanium-containing ceramic product by reacting titanium dioxide with intercalated graphite under conditions which effect said reaction and the reduction of the titanium dioxide and recovering said product which includes therein titanium having a valence less than four.

2. A process according to claim 1 wherein said conditions include a temperature of reaction of at least about 1000°

C. and a time of reaction of at least about 1 hour.

3. A process according to claim 2 wherein said temperature is within the range of about 1000°

C. to about 1375°

C. and said time is within the range of about 1.5 to about 6 hours.

4. A process according to claim 3 wherein said temperature is within the range of about 1200°

C. to about 1300°

C. and said time is within the range of about 2 to about 3 hours.

5. A process according to claim 1 wherein said dioxide and said graphite are reacted in the form of an unshaped powdered mixture and including recovering said product in the form of a powder.

6. A process according to claim 1 including forming a shaped powdered mixture of said dioxide and said graphite and thereafter subjecting said shaped powdered mixture to said conditions of reaction.

7. A process according to claim 6 wherein said shaped powdered mixture is subjected to said conditions of reaction while in porous form and wherein said porous form of said shaped mixture is subjected to said conditions until a reduced form of product is obtained, thereafter sintering said reduced form of product by raising the temperature thereof and recovering said sintered product.

8. A process according to claim 5 wherein said powdered product is formed into a desired shape and is thereafter sintered.

9. A process according to claim 1, 2, 3, 4, 5, 6, 7 or 8 wherein said conditions of reaction include at least one additional reducing agent.

10. A process according to claim 9 wherein hydrogen is included in the reaction as a reducing agent.

11. A process according to claim 1, 2, 3, 4, 5, 6, 7 or 8 wherein said graphite includes a metal intercalant and wherein the metal of said intercalant is combined chemically with said product under the conditions of reaction.

26. A process according to claim 1 wherein said graphite includes a metal intercalant and wherein said metal comprises chromium, copper, nickel, platinum, tantalum, zinc, magnesium, ruthenium, iridium, niobium or vanadium, or a mixture of two or more of said metals.

27. A process according to claim 26 wherein said metal comprises chromium, copper, nickel, platinum or tin, or a mixture of two or more of said metals.

12. A process for producing an electrically-conductive, corrosion-resistant ceramic material which includes titanium in a form having a valence of less than 4 comprising reacting titanium dioxide with intercalated graphite under conditions which effect the reduction of the titanium dioxide, including a temperature of reaction of at least about 1000°

C. and a time of reaction of at least about 1 hour, and recovering said material which includes titanium suboxide and metal combined therewith and derived from said intercalated graphite, and present in an amount sufficient to improve the electrical conductance of said suboxide.

13. A process according to claim 12 wherein said temperature is within the range of about 1000°

C. to about 1375°

C. and said time is within the range of about 1.5 to about 6 hours.

14. A process according to claim 13 wherein said temperature is within the range of about 1200°

C. to about 1300°

C. and said time is within the range of about 2 to about 3 hours.

15. A process according to claim 12, 13, or 14 wherein the reaction is effected under a pressure of about 1.2 to about 4 atmospheres.

16. A process according to claim 12, 13, or 14 wherein at least one additional reducing agent is included in the reaction.

17. A process according to claim 16 wherein hydrogen is included in the reaction as a reducing agent.

18. A process according to claim 12, 13, or 14 including a major amount of titanium dioxide and a minor amount of intercalated graphite.

19. A process according to claim 18 including about 60 to about 95 wt.% of titanium dioxide and about 5 to about 40 wt.% of intercalated graphite.

20. A process according to claim 12, 13, or 14 wherein said intercalated graphite includes an intercalant comprising chromium, copper, nickel, platinum, tantalum, zinc, magnesium, ruthenium, iridium, niobium or vanadium or a mixture of two or more of the aforementioned.

21. A process according to claim 20 wherein the intercalant includes chromium, copper, nickel, platinum, or tantalum or a mixture of two or more of the aforementioned.

22. A process according to claim 13, 14, or 15 in which the intercalant of the intercalated graphite comprises about 5 to about 20 wt.% of the intercalated graphite.

23. A process according to claim 22 wherein said intercalant comprises about 6 to about 10 wt.% of the intercalated graphite.

24. A process according to claim 12, 13, or 15 wherein the reaction is effected under a pressure of about 1.2 to about 4 atmospheres in the presence of hydrogen, and including about 60 to about 95 wt.% of titanium dioxide and about 5 to about 40 wt.% of intercalated graphite, the intercalant of the intercalated graphite comprising about 5 to about 20 wt.% of the intercalated graphite and being selected from the group consisting of chromium, copper, nickel, platinum, tantalum, zinc, magnesium, ruthenium, iridium, niobium and vanadium and a mixture of two or more thereof, and wherein said reaction is effected to produce a material having a resistivity of 1.8×

10^-4 ohm-cm or lower.

25. A process according to claim 24 in which the intercalant is selected from the group consisting of chromium, copper, nickel, platinum and tin and a mixture of two or more thereof.

28. A process for producing a ceramic material which is electrically conductive comprising forming electrically-conductive, ceramic titanium suboxide by reacting titanium dioxide with intercalated graphite under reducing conditions which result in the formation of said titanium suboxide.

29. A process according to claim 28 wherein said conditions include a temperature of reaction of at least about 1000°

C. and a time of reaction of at least about 1 hour.

30. A process according to claim 29 wherein said temperature is within the range of about 1000°

C. to about 1375°

C. and said time is within the range of about 1.5 to about 6 hours.

31. A process according to claim 30 wherein said temperature is within the range of about 1200°

C. to about 1300°

C. and said time is within the range of about 2 to about 3 hours.

32. A process according to claim 28, 29, 30, or 31 wherein the reaction is effected under a pressure of about 1.2 to about 4 atmospheres in the presence of hydrogen, and including about 60 to about 95 wt.% of titanium dioxide and about 5 to about 40 wt.% of intercalated graphite, the intercalant of the intercalated graphite comprising about 5 to about 20 wt.% of the intercalated graphite and being selected from the group consisting of chromium, copper, nickel, platinum, tantalum, zinc, magnesium, ruthenium, iridium, niobium and vanadium and a mixture of two or more thereof, and wherein and reaction is effected to produce a material having a resistivity of 1.8×

10^-4 ohm-cm or lower.