Takaaki O Otagawa

US Patent:

51340429, Jul 28, 1992

Filed:

Jun 14, 1989

Appl. No.:

7/365910

Inventors:

Marc J. Madou - Palo Alto CA
Takaaki Otagawa - Fremont CA
Arden Sher - Foster City CA

Assignee:

SRI International - Menlo Park CA

International Classification:

H01M 810

US Classification:

429 13

Abstract:

The present invention relates to solid materials for use as electrolyte for a fuel cell, or for a sensor, or as a catalyst. Representative structures include lanthanum fluoride, lead potassium fluoride, lead bismuth fluoride, lanthanum strontium fluoride, lanthan strontium lithium fluoride, calcium uranium, cesium fluoride, PbSnFy, KSn. sub. 2 F. sub. 4, SrCl. sub. 2. KCl, LaOF. sub. 2, PbSnF. sub. 8. PbSnO, lanthanum oxyfluoride, oxide, calcium fluoride, SmNdFO, and the like. In another aspect, the present invention relates to a composite and a process to obtain it of the formula: A. sub. 1-y ByQO. sub. 3 having a perovskite or a perovskite-type structure as an electrode catalyst in combination with: A. sub. y B. sub. 1-y F. sub. 2+y as a discontinuous surface coating solid electrolyte solid electrolyte wherein A is independently selected from lanthanum, cerium, neodymium, praseodymium, and scandium, B is independently selected from strontium, calcium barium or magnesium, Q is independently selected from nickel, cobalt, iron or manganese, and y is between about 0. 0001 and 1, which process comprises: (a) obtaining a particulate of: A. sub. 1-y B. sub. y QO. sub.

US Patent:

49486802, Aug 14, 1990

Filed:

May 20, 1988

Appl. No.:

7/196498

Inventors:

Marc J. Madou - Palo Alto CA
Takaaki Otagawa - Fremont CA
Arden Sher - Foster City CA

Assignee:

SRI International - Menlo Park CA

International Classification:

H01M 810

US Classification:

429 13

Abstract:

The present invention relates to solid materials for use as solid electrolytes for a fuel cell. Specifically, the invention relates to a solid O. sup. 2- conducting material for use as an electrolyte for a fuel cell, comprising: a monocrystal or polycrystal structure of the formula: A. sub. 1-x B. sub. x Z, wherein A is independently selected from lanthanum, cerium, neodymium, praseodymium, scandium or mixtures thereof; B is independently selected from strontium, calcium, barium or magnesium, and x is between about 0 and 0. 9999, Z is selected from the group consisting of F. sub. 3-x and O. sub. c F. sub. d where F is fluorine, O is oxygen, x is between about 0 and 0. 9999 and 2c+d=3-x, wherein c is between 0. 0001 and 1.

US Patent:

49004050, Feb 13, 1990

Filed:

Jul 15, 1987

Appl. No.:

7/073712

Inventors:

Takaaki Otagawa - Fremont CA
Marc J. Madou - Palo Alto CA

Assignee:

SRI International - Menlo Park CA

International Classification:

G01N 2726

US Classification:

204 1T

Abstract:

The present invention is concerned with electrode structures and microsensors having fast response times and high sensitivity and to methods using such structures and/or microsensors. This is accomplished in any one of several ways. In one, the sensing and counter electrodes are positioned close enough together on an active area so that ion migration therebetween is fast. The thickness of the electrolytic medium on the active area is restricted to be no more than about 10 microns so that diffusion therethrough between the electrodes is at least as fast as the ion migration. In another, the sensing electrode may have outwardly extending portions extending beyond the electrolytic medium and not being covered thereby. Or, conductive particles can be distributed in the electrolytic medium. Or the medium can be very thin.

US Patent:

47658649, Aug 23, 1988

Filed:

Jul 15, 1987

Appl. No.:

7/073739

Inventors:

Christopher E. Holland - Redwood City CA
Eugene R. Westerberg - Palo Alto CA
Marc J. Madou - Palo Alto CA
Takaaki Otagawa - Fremont CA

Assignee:

SRI International - Menlo Park CA

International Classification:

H01L 21306
B44C 122
C03C 1500
C23F 102

US Classification:

156644

Abstract:

A method is set forth of constructing an electrochemical cell from a crystalline slab having front and back sides facing generally away from one another. Masking layers are provided covering the front and back sides of the slab and a back resist layer is provided covering the front masking layer, the front and resist layer having at least one opening therethrough exposing a portion of the masking layer therebehind. A passage is etched through the exposed part of the back masking layer and extending into the slab to terminate at the front masking layer. A conductor is deposited in the passage. A second front masking layer is formed covering the front side other than where the passage terminates. The masking layers are etched away opposite the passage sufficiently to expose the conductor. The technology provides electrochemical cells either on or completely below the surface of a slab, for example a silicon slab.

US Patent:

51870347, Feb 16, 1993

Filed:

Mar 25, 1991

Appl. No.:

7/675091

Inventors:

Takaaki Otagawa - Fremont CA
Marc J. Madou - Palo Alto CA

Assignee:

Osaka Gas Company Limited

International Classification:

H01M 616
H01M 460

US Classification:

429198

Abstract:

The present invention relates to an electrically conducting polymer, the water-insoluble polymer having essentially permanent self-doping properties, and the polynmer comprises: (a) electrically polymerized polyaniline in covalent combination with (b) an organic dopant having at least one sulfonic acid functional group. The electrically conducting polymer-dopant is preferred wherein the organic dopant is selected from benzenesulfonic acid, toluenesulfonic acid, benzenesulfonyl chloride, dodecylbenzenesulfonic acid, poly(vinylsulfonic) acid, trifluoromethanesulfonic acid, 1-butanesulfonic acid, modified NAFION, 2,3,5-trichlorobenzenesulfonic acid, vinylphenylsulfonic acid, or the alkali metal salts thereof. In another aspect, the present invention discloses a method to produce a water-insoluble polyaniline in which an aromatic organic dopant is covalently bonded to the polyaniline, which method comprises (a) electropolymerizing aniline in an aqueous solvent which contains the organic dopant. These permanently doped polyanilines are useful as films for electric battery electrodes, and for electrochromic applications.

US Patent:

48513032, Jul 25, 1989

Filed:

Nov 26, 1986

Appl. No.:

6/935289

Inventors:

Marc J. Madou - Palo Alto CA
Takaaki Otagawa - Fremont CA
Arden Sher - Foster City CA

Assignee:

SRI-International - Menlo Park CA

International Classification:

H01M 800
H01M 810
G01N 2726

US Classification:

429 13

Abstract:

The present invention relates to solid materials for use as electrolyte for a fuel cell, or for a sensor, or as a catalyst. Representative structures include lanthanum fluoride, lead potassium fluoride, lead bismuth fluoride, lanthanum strontium fluoride, lanthan strontium lithium fluoride, calcium uranium, cesium fluoride, PbSnFy, KSn. sub. 2 F. sub. 4, SrCl. sub. 2. KCl, LaOF. sub. 2, PbSnF. sub. 8. PbSnO, lanthanum oxyfluoride, oxide, calcium fluoride, SmNdFO, and the like. In another aspect, the present invention relates to a composite and a process to obtain it of the formula: A. sub. 1-y ByQO. sub. 3 having a perovskite or a perovskite-type structure as an electrode catalyst in combination with: A. sub. y B. sub. 1-y F. sub. 2+y as a discontinuous surface coating solid electrolyte solid electrolyte wherein A is independently selected from lanthanum, cerium, neodymium, praseodymium, and scandium, B is independently selected from strontium, calcium, barium or magnesium, Q is independently selected from nickel, cobalt, iron or manganese, and y is between about 0. 0001 and 1, which process comprises: (a) obtaining a particulate of: A. sub. 1-y B. sub. y QO. sub.

US Patent:

54036801, Apr 4, 1995

Filed:

Jan 31, 1992

Appl. No.:

7/828414

Inventors:

Takaaki Otagawa - Fremont CA
Marc J. Madou - Palo Alto CA
Leonor A. Wachsman - Palo Alto CA

Assignee:

Osaka Gas Company, Ltd. - Tokyo

International Classification:

H01M 460

US Classification:

429213

Abstract:

The present invention relates to a method to produce a thin film three dimensional microelectrode of an electrically conductive polymer having an organized array of identical microprotrusions, which method comprises: (a) depositing at least one conductive metal thin film on an essentially smooth substrate, (b) depositing a thin film of a micropositive photoresist on the surface of the at least one conductive metal thin film, (c) subjecting the combination of step (b) to photolithographic or electron beam lithographic conditions with a mask capable of producing a metallic microwell, (d) electrochemically polymerizing an electrically conductive polymer onto the conducting metal, (e) removing the photoresist to produce the three dimensional microelectrode array of the electrically conductive polymer. Preferred electrically conductive polymers of step (d) are selected from polypyrrole or polyaniline. The methods wherein in step (d) the polymer is electrochemically polymerized using a constant current, or in step (d) the polymer is electrochemically polymerized using a constant potential, or in step (d), the polymer is electrochemically polymerized using a cyclic potential are preferred.

US Patent:

49733915, Nov 27, 1990

Filed:

Aug 30, 1988

Appl. No.:

7/238571

Inventors:

Marc J. Madou - Palo Alto CA
Takaaki Otagawa - Fremont CA

Assignee:

Osaka Gas Company, Ltd. - Osaka

International Classification:

C25B 302

US Classification:

204 78

Abstract:

The present invention relates to a process for the production of an electrochromic electrically conductive composite membrane, which process comprises: (a) combining aniline and metal phthalocyanine in dilute hydrochloric acid; and (b) applying to the solution of step (a) a constant current density of between about 0. 05 and 0. 2 milliamperes/cm. sup. 2 for between about 1 to 10 minutes on an electrode selected from a transparent platinum electrode or an ITO electrode to produce the improved electrically conductive electrochromic membrane. The present invention also relates to a process for the production of an electrically conductive composite membrane which comprises: (a) combining aniline, organic sulfonic acid and NAFION. RTM. all in the acid form and electropolymerizing the aqueous solution to obtain the polyaniline thin film. The electrochromic electrically conductive composite membrane produced by the process is described which is colorless when subjected to between about -0.